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Mauro Giavalisco

Galaxies: evolution

Articles 1 - 30 of 45

Full-Text Articles in Physical Sciences and Mathematics

The Herschel View Of The Dominant Mode Of Galaxy Growth From Z=4 To The Present Day, C. Schreiber, M. Pannella, D. Elbaz, M. Bethermin, H. Inami, M. Dickinson, B. Magnelli, T. Wang, H. Aussel, E. Daddi, S Juneau, X. Shu, M. T. Sargent, V. Buat, S.M. Faber, H.C. Ferguson, Mauro Giavalisco, A.M. Koekemoer, G. Magdis, G.E. Morrison, C. Papovich, P. Santini, D. Scott Jan 2015

The Herschel View Of The Dominant Mode Of Galaxy Growth From Z=4 To The Present Day, C. Schreiber, M. Pannella, D. Elbaz, M. Bethermin, H. Inami, M. Dickinson, B. Magnelli, T. Wang, H. Aussel, E. Daddi, S Juneau, X. Shu, M. T. Sargent, V. Buat, S.M. Faber, H.C. Ferguson, Mauro Giavalisco, A.M. Koekemoer, G. Magdis, G.E. Morrison, C. Papovich, P. Santini, D. Scott

Mauro Giavalisco

No abstract provided.


Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z~3.3, B.C. Lemaux, O. Cucciati, L.A.M. Tasca, O. Le Fevre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R.R. Gal, D.D. Kocevski, C. Lopez-Sanjuan, L.M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville Dec 2014

Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z~3.3, B.C. Lemaux, O. Cucciati, L.A.M. Tasca, O. Le Fevre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R.R. Gal, D.D. Kocevski, C. Lopez-Sanjuan, L.M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville

Mauro Giavalisco

Using new spectroscopic observations obtained as part of the VIMOS Ultra-Deep Survey (VUDS), we performed a systematic search for overdense environments in the early universe (z> 2) and report here on the discovery of Cl J0227-0421, a massive protocluster at z = 3.29. This protocluster is characterized by both the large overdensity of spectroscopically confirmed members, δgal = 10.5 ± 2.8, and a significant overdensity in photometric redshift members. The halo mass of this protocluster is estimated by a variety of methods to be ~3 × 1014ℳ⊙ at z ~ 3.3, which, evolved to z = 0 results in a …


Properties Of Submillimeter Galaxies In The Candels Goods-South Field, Tommy Wiklind, Christopher J. Conselice, Thomas Dahlen, Mark E. Dickinson, Henry C. Ferguson, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Bahram Mobasher, Alice Mortlock, Adriano Fontana, Romeel Dave, Haojin Yan, Viviana Aequaviva, Matthew L.N. Ashby, Guillermo Barro, Karina L. Caputi, Marco Castellano, Avishai Dekel, Jennifer L. Donley, Giovanni G. Fazio, Mauro Giavalisco, Andrea Grazian, Nimish P. Hathi, Peter Kurezynski, Yu Lu, Elizabeth J. Mcgrath, Duilia F. De Mello, Michael Peth, Mohammed Sarafzedeh, Mauro Stefanon, Thomas Targett Feb 2014

Properties Of Submillimeter Galaxies In The Candels Goods-South Field, Tommy Wiklind, Christopher J. Conselice, Thomas Dahlen, Mark E. Dickinson, Henry C. Ferguson, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Bahram Mobasher, Alice Mortlock, Adriano Fontana, Romeel Dave, Haojin Yan, Viviana Aequaviva, Matthew L.N. Ashby, Guillermo Barro, Karina L. Caputi, Marco Castellano, Avishai Dekel, Jennifer L. Donley, Giovanni G. Fazio, Mauro Giavalisco, Andrea Grazian, Nimish P. Hathi, Peter Kurezynski, Yu Lu, Elizabeth J. Mcgrath, Duilia F. De Mello, Michael Peth, Mohammed Sarafzedeh, Mauro Stefanon, Thomas Targett

Mauro Giavalisco

We derive physical properties of 10 submillimeter galaxies located in the CANDELS coverage of the GOODS-South Field. The galaxies were first identified as sub- millimeter sources with the LABOCA bolometer and subsequently targeted for 870µm continuum observation with ALMA. The high angular resolution of the ALMA imaging allows secure counterparts to be identified in the CANDELS multiband dataset. The CANDELS data provide deep photometric data from UV through near-infrared wavelengths. Using synthetic spectral energy distributions, we derive photometric redshifts, stellar masses, extinction, ages, and the star formation history. The redshift range is z=1.65-4.76, with two of the galaxies located at …


The Vimos Ultra-Deep Survey (Vuds): Fast Increase In The Fraction Of Strong Lyman-Α Emitters From Z=2 To Z=6, P. Cassata, L.A.M. Tasca, O. Le Fevre, C. Lemaux, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, A. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, O. Cucciati, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville Jan 2014

The Vimos Ultra-Deep Survey (Vuds): Fast Increase In The Fraction Of Strong Lyman-Α Emitters From Z=2 To Z=6, P. Cassata, L.A.M. Tasca, O. Le Fevre, C. Lemaux, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, A. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, O. Cucciati, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville

Mauro Giavalisco

Aims. The aim of this work is to constrain the evolution of the fraction of strong Lyα emitters among UV selected star-forming galaxies at 2 25 Å to increase from ~5% at z ~ 2 to ~30% at z ~ 6, with the increase being stronger beyond z ~ 4. We observe no difference, for the narrow range of UV luminosities explored in this work, between the fraction of strong Lyα emitters among galaxies fainter or brighter than M*FUV, although the fraction for the faint galaxies evolves faster, at 2


The Hawk-I Uds And Goods Survey (Hugs): Survey Design And Deep K-Band Number Counts, A. Fontana, J.S. Dunlop, D. Paris, T.A. Targett, K. Boutsia, M. Castellano, A. Galametz, A. Grazian, R. Mclure, E. Merlin, L. Pentericci, S. Wuyts, O. Almaini, K. Caputi, R.R. Chary, M. Cirasuolo, C.J. Conselice, A. Cooray, E. Daddi, M. Dickinson, S.M. Faber, G. Fazio, H.C. Ferguson, E. Giallongo, Mauro Giavalisco, N.A. Grogin, N. Hathi, A.M. Koekemoer, D.C. Koo, R.A. Lucas, M. Nonino, H.W. Rix, A. Renzini, D. Rosario, P. Santini, C. Scarlata, V. Sommariva, D.P. Stark, A. Van Der Wel, E. Vanzella, V. Wild, H. Yan, S Zibetti Jan 2014

The Hawk-I Uds And Goods Survey (Hugs): Survey Design And Deep K-Band Number Counts, A. Fontana, J.S. Dunlop, D. Paris, T.A. Targett, K. Boutsia, M. Castellano, A. Galametz, A. Grazian, R. Mclure, E. Merlin, L. Pentericci, S. Wuyts, O. Almaini, K. Caputi, R.R. Chary, M. Cirasuolo, C.J. Conselice, A. Cooray, E. Daddi, M. Dickinson, S.M. Faber, G. Fazio, H.C. Ferguson, E. Giallongo, Mauro Giavalisco, N.A. Grogin, N. Hathi, A.M. Koekemoer, D.C. Koo, R.A. Lucas, M. Nonino, H.W. Rix, A. Renzini, D. Rosario, P. Santini, C. Scarlata, V. Sommariva, D.P. Stark, A. Van Der Wel, E. Vanzella, V. Wild, H. Yan, S Zibetti

Mauro Giavalisco

We present the results of a new, ultra-deep, near-infrared imaging survey executed with the Hawk-I imager at the ESO VLT, of which we make all the data (images and catalog) public. This survey, named HUGS (Hawk-I UDS and GOODS Survey), provides deep, high-quality imaging in the K and Y bands over the portions of the UKIDSS UDS and GOODS-South fields covered by the CANDELS HST WFC3/IR survey. In this paper we describe the survey strategy, the observational campaign, the data reduction process, and the data quality. We show that, thanks to exquisite image quality and extremely long exposure times, HUGS …


Probing Outflows In Z = 1~2 Galaxies Through Fe Ii/Fe Ii Multiplets, Yuping Tang, Mauro Giavalisco, Yicheng Guo, Jaron Kurk Jan 2014

Probing Outflows In Z = 1~2 Galaxies Through Fe Ii/Fe Ii Multiplets, Yuping Tang, Mauro Giavalisco, Yicheng Guo, Jaron Kurk

Mauro Giavalisco

We report on a study of the 2300 − 2600°A Fe II/Fe II∗ multiplets in the rest–UV spectra of star forming galaxies at 1.0 < z < 2.6 as probes of galactic–scale outflows. We extracted a mass–limited sample of 97 galaxies at z _ 1.0 − 2.6 from ultra–deep spectra obtained during the GMASS spetroscopic survey in the GOODS South field with the VLT and FORS2. We obtain robust measures of the rest equivalent width of the Fe II absorption lines down to a limit of Wr > 1.5°A and of the Fe II∗ emission lines to Wr > 0.5°A. Whenever we can measure the systemic redshift of the galaxies from the [O II] emission line, we find that both the Fe II and Mg II absorption lines are blueshifted, indicative that both species trace gaseous outflows. We also find, however, that the Fe II gas has generally lower outflow velocity relative to that of Mg II. We investigate the variation of Fe II line …


The Mass Evolution Of The First Galaxies: Stellar Mass Functions And Star Formation Rates At 4 < Z < 7 In The Candels Goods-South Field, K. Duncan, C.J. Conselice, A. Mortlock, W.G. Hartley, Y. Guo, H.C. Ferguson, R. Dave, Y. Lu, J. Ownsworth, M.L.N. Ashby, A. Dekel, M. Dickinson, S. Faber, Mauro Giavalisco, N. Grogin, D. Kocevski, A. Koekemoer, R.S. Somerville, C.E. White Jan 2014

The Mass Evolution Of The First Galaxies: Stellar Mass Functions And Star Formation Rates At 4 < Z < 7 In The Candels Goods-South Field, K. Duncan, C.J. Conselice, A. Mortlock, W.G. Hartley, Y. Guo, H.C. Ferguson, R. Dave, Y. Lu, J. Ownsworth, M.L.N. Ashby, A. Dekel, M. Dickinson, S. Faber, Mauro Giavalisco, N. Grogin, D. Kocevski, A. Koekemoer, R.S. Somerville, C.E. White

Mauro Giavalisco

We measure new estimates for the galaxy stellar mass function and star formation rates for samples of galaxies at z ~ 4; 5; 6 & 7 using data in the CANDELS GOODS South-field. The deep near-infrared observations allow us to construct the stellar mass function at z > 6 directly for the first time. We estimate stellar masses for our sample by fitting the observed spectral energy distributions with synthetic stellar populations, including nebular line and continuum emission. The observed UV luminosity functions for the samples are consistent with previous observations, however we find that the observed MUV - M_ relation …


The Vimos Ultra-Deep Survey (Vuds): Igm Transmission Towards Galaxies With 2.5, R. Thomas, O. Le Fevre, V. Le Brun, P. Cassata, B. Garilli, C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, G. Zamorani, R. Amorin, S. Bardelli, L. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, S. Paltani, B. Ribeiro, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, L. Tresse, E. Vanzella, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, S. De La Torre, J. Dunlop, S. Fotopoulou, A. Koekemoer, C. Lopez-Sanjuan, Y. Mellier, J. Pforr, M. Salvato, N. Scoville, Y. Taniguchi, P.W. Wang Jan 2014

The Vimos Ultra-Deep Survey (Vuds): Igm Transmission Towards Galaxies With 2.5, R. Thomas, O. Le Fevre, V. Le Brun, P. Cassata, B. Garilli, C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, G. Zamorani, R. Amorin, S. Bardelli, L. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, S. Paltani, B. Ribeiro, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, L. Tresse, E. Vanzella, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, S. De La Torre, J. Dunlop, S. Fotopoulou, A. Koekemoer, C. Lopez-Sanjuan, Y. Mellier, J. Pforr, M. Salvato, N. Scoville, Y. Taniguchi, P.W. Wang

Mauro Giavalisco

The observed UV rest-frame spectra of distant galaxies are the result of their intrinsic emission combined with absorption along the line of sight produced by the inter-galactic medium (IGM). Here we analyse the evolution of the mean IGM transmission Tr(Ly_alpha) and its dispersion along the line of sight for 2127 galaxies with 2.5= 4 compared to results from QSOs, but a degeneracy between dust extinction and IGM prevents to draw firm conclusions if the internal dust extinction for star-forming galaxies at z>4 takes a mean value significantly in excess of E(B-V)>0.15. Most importantly, we find a large dispersion …


The Vimos Ultra-Deep Survey (Vuds): ~10,000 Galaxies With Spectroscopic Redshifts To Study Galaxy Assembly At Early Epochs 2 < Z ≈ 6, O. Le Fevre, L.A.M. Tasca, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, O. Cucciati, S. De La Torre, A Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, B.C. Lemaux, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville Jan 2014

The Vimos Ultra-Deep Survey (Vuds): ~10,000 Galaxies With Spectroscopic Redshifts To Study Galaxy Assembly At Early Epochs 2 < Z ≈ 6, O. Le Fevre, L.A.M. Tasca, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, O. Cucciati, S. De La Torre, A Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, B.C. Lemaux, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville

Mauro Giavalisco

We present the VIMOS Ultra Deep Survey (VUDS), a spectroscopic redshift survey of ~10 000 very faint galaxies to study the main phase of galaxy assembly in 2 < z ≃ 6. The survey covers 1 deg2 in three separate fields: COSMOS, ECDFS, and VVDS-02h, with the selection of targets based on an inclusive combination of photometric redshifts and colour properties. Spectra covering 3650 < λ < 9350 Å are obtained with VIMOS on the ESO-VLT with integration times of 14h. Here we present the survey strategy, target selection, data processing, and the redshift measurement process with an emphasis on the specific methods used to adapt to this high-redshift range. We discuss the spectra quality and redshift reliability and derive a success rate in redshift measurement of 91%, or 74% by limiting the dataset to the most reliable measurements, down to a limiting magnitude iAB = 25. Measurements are performed all the way down to iAB = 27. The mean redshift of the main sample is z ~ 3 and extends over a broad redshift range mainly in 2 < z < 6. At 3 < z < 5, the galaxies cover a wide range of luminosities −23 < MNUV < −20.5, stellar mass 109M⊙ < M∗ < 1011M⊙, and star formation rates 1M⊙/yr < SFR < 103M⊙/yr. We discuss the spectral properties of galaxies using individual as well asstacked spectra. The comparison between spectroscopic and photometric redshifts as well as colour selection demonstrate the effectiveness of our selection scheme. From about ~ 90% of the data analysed so far, we expect to assemble >6000 galaxies with reliable spectroscopic redshifts in 2 < z < 6 when complete. This makes the VUDS the largest survey at these redshifts and offers the opportunity for unprecedented studies of the star-forming galaxy population and its distribution in large-scale structures during the main phase of galaxy assembly.


The Relation Between Star Formation Rate And Stellar Mass For Galaxies At 3.5 < Z < 6.5 In Candels, Brett Salmon, Casey Papovich, Steven L. Finkelstein, Vithal Tilvi, Kristian Flinator, Peter Behroozi, Tomas Dahlen, Romeel Dave, Avishai Dekel, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, James Long, Yu Lu, Bahram Mobasher, Naveen Reddy, Rachel S. Somerville, Risa H. Wechsler Jan 2014

The Relation Between Star Formation Rate And Stellar Mass For Galaxies At 3.5 < Z < 6.5 In Candels, Brett Salmon, Casey Papovich, Steven L. Finkelstein, Vithal Tilvi, Kristian Flinator, Peter Behroozi, Tomas Dahlen, Romeel Dave, Avishai Dekel, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, James Long, Yu Lu, Bahram Mobasher, Naveen Reddy, Rachel S. Somerville, Risa H. Wechsler

Mauro Giavalisco

No abstract provided.


The Size-Luminosity Relation At Z=7 In Candels And Its Implication On Reionization, A. Grazian, M. Castellano, A. Fontana, L. Pentericci, J. S. Dunlop, R. J. Mclure, A. M. Koekemoer, M. E. Dickinson, S. M. Faber, H. C. Ferguson, A. Galametz, Mauro Giavalisco, N. A. Grogin, N. P. Hathi, D. D. Kocevski, K. Lai, J. A. Newman, E. Vanzella Jan 2012

The Size-Luminosity Relation At Z=7 In Candels And Its Implication On Reionization, A. Grazian, M. Castellano, A. Fontana, L. Pentericci, J. S. Dunlop, R. J. Mclure, A. M. Koekemoer, M. E. Dickinson, S. M. Faber, H. C. Ferguson, A. Galametz, Mauro Giavalisco, N. A. Grogin, N. P. Hathi, D. D. Kocevski, K. Lai, J. A. Newman, E. Vanzella

Mauro Giavalisco

The exploration of the relation between galaxy sizes and other physical parameters has given important clues to understand the galaxy formation processes. We use the CANDELS Deep+Wide surveys in the GOODS-South, UDS and EGS fields, complemented by data from the HUDF09 program, to address the relation between size and luminosity at z\sim7. We select 153 z-band drop-out galaxies in six different fields characterized by a wide combination of depth and areal coverage, ideally suited to sample without biases the observed size-magnitude plane. Detailed simulations allow us to derive the completeness as a function of sizes and magnitudes and to quantify …


Color And Stellar Population Gradients In Passively Evolving Galaxies At Z~2 From Hst/Wfc3 Deep Imaging In The Hubble Ultra Deep Field, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Mark Dickinson, Alvio Renzini, Anton Koekemoer, Norman A. Grogin, Casey Papovich, Elena Tundo, Adriano Fontana, Jennifer M. Lotz, Sara Salimbeni Jan 2011

Color And Stellar Population Gradients In Passively Evolving Galaxies At Z~2 From Hst/Wfc3 Deep Imaging In The Hubble Ultra Deep Field, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Mark Dickinson, Alvio Renzini, Anton Koekemoer, Norman A. Grogin, Casey Papovich, Elena Tundo, Adriano Fontana, Jennifer M. Lotz, Sara Salimbeni

Mauro Giavalisco

We report the detection of color gradients in six massive (stellar mass > 10^{10} M_{sun}) and passively evolving (specific SFR < 10^{-11}/yr) galaxies at redshift 1.3


How Do Star-Forming Galaxies At Z>3 Assemble Their Masses?, Kyoung-Soo Lee, Henry C. Ferguson, Tommy Wiklind, Tomas Dahlen, Mark E. Dickinson, Mauro Giavalisco, Normin Grogin, Casey Papovich, Hugo Messias, Yicheng Guo, Lihwai Lin Jan 2011

How Do Star-Forming Galaxies At Z>3 Assemble Their Masses?, Kyoung-Soo Lee, Henry C. Ferguson, Tommy Wiklind, Tomas Dahlen, Mark E. Dickinson, Mauro Giavalisco, Normin Grogin, Casey Papovich, Hugo Messias, Yicheng Guo, Lihwai Lin

Mauro Giavalisco

We investigate how star-forming galaxies typically assemble their masses at high redshift. Using the deep multi-wavelength coverage of the GOODS dataset, we measure stellar mass of a large sample of star-forming galaxies at z~4 and 5, and make a robust determination of stellar mass function (SMF). We report a broad correlation between stellar mass and UV luminosity, such that more UV-luminous galaxies are, on average, more massive. However, the correlation has a substantial intrinsic scatter evidenced by a non-negligible number of UV-faint but massive galaxies. Furthermore, the low-mass end of the SMF does not rise as steeply as the UV …


Candels: The Evolution Of Galaxy Rest-Frame Ultraviolet Colors From Z = 8 To 4, Steven L. Finkelstein, Casey Papovich, Brett Salmon, Kristian Finlator, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Anton M. Koekemoer, Naveen A. Reddy, Robert Bassett, Christopher J. Conselice, James C. Dunlop, S. M. Faber, Norman A. Grogin, Nimish P. Hathi, Dale D. Kocevski, Kamson Lai, Kyoung-Soo Lee, Ross J. Mclure, Bahram Mobasher, Jeffrey A. Newman Jan 2011

Candels: The Evolution Of Galaxy Rest-Frame Ultraviolet Colors From Z = 8 To 4, Steven L. Finkelstein, Casey Papovich, Brett Salmon, Kristian Finlator, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Anton M. Koekemoer, Naveen A. Reddy, Robert Bassett, Christopher J. Conselice, James C. Dunlop, S. M. Faber, Norman A. Grogin, Nimish P. Hathi, Dale D. Kocevski, Kamson Lai, Kyoung-Soo Lee, Ross J. Mclure, Bahram Mobasher, Jeffrey A. Newman

Mauro Giavalisco

We study the evolution of galaxy rest-frame ultraviolet (UV) colors in the epoch 4 < z < 8. We use new wide-field near-infrared data in GOODS-S from the CANDELS, HUDF09 and ERS programs to select galaxies via photometric redshift measurements. Our sample consists of 2812 candidate galaxies at z > 3.5, including 113 at z = 7 to 8. We fit the observed spectral energy distribution to a suite of synthetic stellar population models, and measure the value of the UV spectral slope (beta) from the best-fit model spectrum. The median value of beta evolves significantly from -1.82 (+0.00,-0.04) at z = 4, to -2.37 (+0.26,-0.06) at z = 7. Additionally, we find that faint galaxies at z = 7 have beta = -2.68 (+0.39,-0.24) (~ -2.4 after correcting for observational bias); this is redder than …


What Turns Galaxies Off? The Different Morphologies Of Star-Forming And Quiescent Galaxies Since Z~2 From Candels, Eric F. Bell, Arjen Van Der Wel, Casey Papovich, Dale Kocevski, Jennifer Lotz, Daniel H. Mcintosh, Jeyhan Kartaltepe, S. M. Faber, Harry Ferguson, Anton Koekemoer, Norman Grogin, Stijn Wuyts, Edmond Cheung, Christopher J. Conselice, Avishai Dekel, James S. Dunlop, Mauro Giavalisco, Mauro Giavalisco, Jessica Herrington, David C. Koo, Elizabeth J. Mcgrath, Duilia De Mello, Hans-Walter Rix, Aday R. Robaina, Christina C. Williams Jan 2011

What Turns Galaxies Off? The Different Morphologies Of Star-Forming And Quiescent Galaxies Since Z~2 From Candels, Eric F. Bell, Arjen Van Der Wel, Casey Papovich, Dale Kocevski, Jennifer Lotz, Daniel H. Mcintosh, Jeyhan Kartaltepe, S. M. Faber, Harry Ferguson, Anton Koekemoer, Norman Grogin, Stijn Wuyts, Edmond Cheung, Christopher J. Conselice, Avishai Dekel, James S. Dunlop, Mauro Giavalisco, Mauro Giavalisco, Jessica Herrington, David C. Koo, Elizabeth J. Mcgrath, Duilia De Mello, Hans-Walter Rix, Aday R. Robaina, Christina C. Williams

Mauro Giavalisco

We use HST/WFC3 imaging from the CANDELS Multicycle Treasury Survey, in conjunction with the Sloan Digital Sky Survey, to explore the evolution of galactic structure for galaxies with stellar masses >3e10M_sun from z=2.2 to the present epoch, a time span of 10Gyr. We explore the relationship between rest-frame optical color, stellar mass, star formation activity and galaxy structure. We confirm the dramatic increase from z=2.2 to the present day in the number density of non-star-forming galaxies above 3e10M_sun reported by others. We further find that the vast majority of these quiescent systems have concentrated light profiles, as parametrized by the …


The Nature Of Extremely Red H-[4.5]>4 Galaxies Revealed With Seds And Candels, K. I. Caputi, J. S. Dunlop, R. J. Mclure, J, -S. Huang, G. G. Fazio, M. L. N. Ashby, M. Castellano, A. Fontana, M. Cirasuolo, O. Almaini, E. F. Bell, M. Dickinson, J. L. Donley, S. M. Faber, H. C. Ferguson, Mauro Giavalisco, N. A. Grogin, D. D. Kocevski, A. M. Koekemoer, D C. Koo, K. Lai, J. A. Newman, R. S. Somerville Jan 2011

The Nature Of Extremely Red H-[4.5]>4 Galaxies Revealed With Seds And Candels, K. I. Caputi, J. S. Dunlop, R. J. Mclure, J, -S. Huang, G. G. Fazio, M. L. N. Ashby, M. Castellano, A. Fontana, M. Cirasuolo, O. Almaini, E. F. Bell, M. Dickinson, J. L. Donley, S. M. Faber, H. C. Ferguson, Mauro Giavalisco, N. A. Grogin, D. D. Kocevski, A. M. Koekemoer, D C. Koo, K. Lai, J. A. Newman, R. S. Somerville

Mauro Giavalisco

We have analysed a sample of 25 extremely red H-[4.5]>4 galaxies, selected using 4.5 micron data from the Spitzer SEDS survey and deep H-band data from the Hubble Space Telescope (HST) CANDELS survey, over ~180 square arcmin of the UKIDSS Ultra Deep Survey (UDS) field. Our aim is to investigate the nature of this rare population of mid-infrared (mid-IR) sources that display such extreme near-to-mid-IR colours. Using up to 17-band photometry (U through 8.0 microns), we have studied in detail their spectral energy distributions, including possible degeneracies in the photometric redshift/internal extinction (zphot-Av) plane. Our sample appears to include …


Rest-Frame Uv--Optically Selected Galaxies At 2.3, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Christina C. Williams, Mark Dickinson, Anton Koekemoer, Norman A. Grogin, Ranga-Ram Chary, Hugo Messias, Elena Tundo, Lihwai Lin, Seong-Kook Lee, Adriano Fontana, Andrea Grazian, Dale Kocevski, Kyoung-Soo Lee, Edward Villanueva, Arjen Van Der Wel Jan 2011

Rest-Frame Uv--Optically Selected Galaxies At 2.3, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Christina C. Williams, Mark Dickinson, Anton Koekemoer, Norman A. Grogin, Ranga-Ram Chary, Hugo Messias, Elena Tundo, Lihwai Lin, Seong-Kook Lee, Adriano Fontana, Andrea Grazian, Dale Kocevski, Kyoung-Soo Lee, Edward Villanueva, Arjen Van Der Wel

Mauro Giavalisco

A new set of color selection criteria (VJL) analogous with the BzK method is designed to select both star-forming galaxies (SFGs) and passively-evolving galaxies (PEGs) at 2.310^{10}M_{Sun}) galaxies at 2.30.4) SFGs, which however, only account for ~20% of the number density of massive SFGs. We also use the mid-infrared fluxes to clean our PEG sample, and find that galaxy size can be used as a secondary criterion to effectively eliminate the contamination of dusty SFGs. The redshift distribution of the cleaned PEG sample peaks at z~2.5. We find 6 PEG candidates at z>3 and discuss possible methods to distinguish …


On The Clustering Of Sub-Millimeter Galaxies, Christina C. Williams, Mauro Giavalisco, Cristiano Porciani, Min S. Yun, Alexandra Pope, Kimberly S. Scott, Jason E. Austermann, Itziar Aretxaga, Bunyo Hatsukade, Kyoung-Soo Lee, Grant W. Wilson, J. Ryan Cybulski, David H. Hughes, Ryo Kawabe, Kotaro Kohno, Thushara Perera, F. Peter Schloerb Jan 2011

On The Clustering Of Sub-Millimeter Galaxies, Christina C. Williams, Mauro Giavalisco, Cristiano Porciani, Min S. Yun, Alexandra Pope, Kimberly S. Scott, Jason E. Austermann, Itziar Aretxaga, Bunyo Hatsukade, Kyoung-Soo Lee, Grant W. Wilson, J. Ryan Cybulski, David H. Hughes, Ryo Kawabe, Kotaro Kohno, Thushara Perera, F. Peter Schloerb

Mauro Giavalisco

We measure the angular two-point correlation function of sub-millimeter galaxies (SMGs) from 1.1-millimeter imaging of the COSMOS field with the AzTEC camera and ASTE 10-meter telescope. These data yields one of the largest contiguous samples of SMGs to date, covering an area of 0.72 degrees^2 down to a 1.26 mJy/beam (1-sigma) limit, including 189 (328) sources with S/N greater than 3.5 (3). We can only set upper limits to the correlation length r_0, modeling the correlation function as a power-law with pre-assigned slope. Assuming existing redshift distributions, we derive 68.3% confidence level upper limits of r_0 < 6-8 h^-1 Mpc at 3.7 mJy, and r_0 < 11-12 h^-1 Mpc at 4.2 mJy. Although consistent with most previous estimates, these upper limits imply that the real r_0 is likely smaller. This casts doubts on the robustness of claims that SMGs are characterized by significantly stronger spatial clustering, (and thus larger mass), than differently selected galaxies at high-redshift. Using Monte Carlo simulations we show that even strongly clustered distributions of galaxies can appear unclustered when sampled with limited sensitivity and coarse angular resolution common to current sub-millimeter surveys. The simulations, however, also show that unclustered distributions can appear strongly clustered under these circumstances. From the simulations, we predict that at our survey depth, a mapped area of two degrees^2 is needed to reconstruct the correlation function, assuming smaller beam sizes of future surveys (e.g. the Large Millimeter Telescope's 6" beam size). At present, robust measures of the clustering strength of bright SMGs appear to be below the reach of most observations.


Deep Near-Infrared Spectroscopy Of Passively Evolving Galaxies At Z & 1.4^1, M. Onodera, A. Renzini, M. Carollo, M. Cappellari, C. Mancini, V. Strazzullo, E. Daddi, N. Arimoto, R. Gobat, Y. Yamada, H. J. Mccracken, O. Ilbert, P. Capak, A. Cimatti, Mauro Giavalisco, M. Giavalisco, A. M. Koekemoer, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi Jan 2011

Deep Near-Infrared Spectroscopy Of Passively Evolving Galaxies At Z & 1.4^1, M. Onodera, A. Renzini, M. Carollo, M. Cappellari, C. Mancini, V. Strazzullo, E. Daddi, N. Arimoto, R. Gobat, Y. Yamada, H. J. Mccracken, O. Ilbert, P. Capak, A. Cimatti, Mauro Giavalisco, M. Giavalisco, A. M. Koekemoer, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi

Mauro Giavalisco

We present the results of new near-IR spectroscopic observations of passive galaxies at z & 1.4 in a concentration of BzK-selected galaxies in the COSMOS field. The observations have been conducted with Subaru/ MOIRCS, and have resulted in absorption lines and/or continuum detection for 18 out of 34 objects. This allows us to measure spectroscopic redshifts for a sample that is almost complete to KAB = 21. COSMOS photometric redshifts are found in fair agreement overall with the spectroscopic redshifts, with a standard deviation of ∼ 0.05; however, ∼ 30% of objects have photometric redshifts systematically underestimated by up to …


Goods-Herschel: An Infrared Main Sequence For Star-Forming Galaxies, D. Elbaz, M. Dickinson, H. S. Hwang, T. Díaz-Santos, G. Magdis, B. Magnelli, D. Le Borgne, F. Galliano, M. Pannella, P. Chanial, L. Armus, V. Charmandaris, E. Daddi, H. Aussel, P. Popesso, J. Kartaltepe, B. Altieri, I. Valtchanov, D. Coia, H. Dannerbauer, K. Dasyra, R. Leiton, J. Mazzarella, D. M. Alexander, V. Buat, D. Burgarella, R-R. Chary, R. Gilli, R. J. Ivison, S. Juneau, E. Le Floc'h, D. Lutz, G. E. Morrison, J. R. Mullaney, E. Murphy, A. Pope, D. Scott, M. Brodwin, D. Calzetti, C. Cesarsky, S. Charlot, H. Dole, P. Eisenhardt, H. C. Ferguson, N. Förster Schreiber, D. Frayer, Mauro Giavalisco, M. Huynh, A. M. Koekemoer, C. Papovich, N. Reddy, C. Surace, H. Teplitz, M. S. Yun, G. Wilson Jan 2011

Goods-Herschel: An Infrared Main Sequence For Star-Forming Galaxies, D. Elbaz, M. Dickinson, H. S. Hwang, T. Díaz-Santos, G. Magdis, B. Magnelli, D. Le Borgne, F. Galliano, M. Pannella, P. Chanial, L. Armus, V. Charmandaris, E. Daddi, H. Aussel, P. Popesso, J. Kartaltepe, B. Altieri, I. Valtchanov, D. Coia, H. Dannerbauer, K. Dasyra, R. Leiton, J. Mazzarella, D. M. Alexander, V. Buat, D. Burgarella, R-R. Chary, R. Gilli, R. J. Ivison, S. Juneau, E. Le Floc'h, D. Lutz, G. E. Morrison, J. R. Mullaney, E. Murphy, A. Pope, D. Scott, M. Brodwin, D. Calzetti, C. Cesarsky, S. Charlot, H. Dole, P. Eisenhardt, H. C. Ferguson, N. Förster Schreiber, D. Frayer, Mauro Giavalisco, M. Huynh, A. M. Koekemoer, C. Papovich, N. Reddy, C. Surace, H. Teplitz, M. S. Yun, G. Wilson

Mauro Giavalisco

We present the deepest far-IR observations obtained with Herschel and examine the 3-500um SEDs of galaxies at 03x10^10 Lsun kpc^-2) and a high specific SFR (i.e., SBs). The rest-frame, UV-2700A size of these distant SBs is typically half that of MS galaxies, supporting the correlation between star formation density and SB activity that is measured for the local sample. Locally, (U)LIRGs are systematically in the SB mode, whereas most distant (U)LIRGs form stars in the "normal" MS mode. This confusion between two modes of star formation is the cause of the so-called "mid-IR excess" population of galaxies found at z …


Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson Jan 2010

Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson

Mauro Giavalisco

We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy, we resolve 31--45 per …


A Spectroscopic Search For Leaking Lyman Continuum At Z~0.7, Carrie R. Bridge, Harry I. Teplitz, Brian Siana, Claudia Scarlata, Christopher J. Conselice, Henry C. Ferguson, Thomas M. Brown, Mara Salvato, Gwen C. Rudie, Duilia F. De Mello, James Colbert, Jonathan P. Gardner, Mauro Giavalisco, Lee Armus Jan 2010

A Spectroscopic Search For Leaking Lyman Continuum At Z~0.7, Carrie R. Bridge, Harry I. Teplitz, Brian Siana, Claudia Scarlata, Christopher J. Conselice, Henry C. Ferguson, Thomas M. Brown, Mara Salvato, Gwen C. Rudie, Duilia F. De Mello, James Colbert, Jonathan P. Gardner, Mauro Giavalisco, Lee Armus

Mauro Giavalisco

We present the results of rest-frame, UV slitless spectroscopic observations of a sample of 32 z~0.7 Lyman break galaxy (LBG) analogs in the COSMOS field. The spectroscopic search was performed with the Solar Blind Channel (SBC) on Hubble Space Telescope. We report the detection of leaking Lyman continuum (LyC) radiation from an AGN-starburst composite. While we find no direct detections of LyC emission in the remainder of our sample, we achieve individual lower limits (3 sigma) of the observed non-ionizing UV to LyC flux density ratios, f_{nu}(1500A)/f_{nu}(830A) of 20 to 204 (median of 73.5) and 378.7 for the stack. Assuming …


Improving The Estimation Of Star Formation Rates And Stellar Population Ages Of High-Redshift Galaxies From Broadband Photometry, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco Jan 2010

Improving The Estimation Of Star Formation Rates And Stellar Population Ages Of High-Redshift Galaxies From Broadband Photometry, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco

Mauro Giavalisco

We explore methods to improve the estimates of star formation rates and mean stellar population ages from broadband photometry of high redshift star-forming galaxies. We use synthetic spectral templates with a variety of simple parametric star formation histories to fit broadband spectral energy distributions. These parametric models are used to infer ages, star formation rates and stellar masses for a mock data set drawn from a hierarchical semi-analytic model of galaxy evolution. Traditional parametric models generally assume an exponentially declining rate of star-formation after an initial instantaneous rise. Our results show that star formation histories with a much more gradual …


The Bright End Of The Z ~ 7 Uv Luminosity Function From A Wide And Deep Hawk-I Survey, M. Castellano, A. Fontana, D. Paris, A. Grazian, L. Pentericci, K. Boutsia, P. Santini, V. Testa, M. Dickinson, Mauro Giavalisco, R. Bouwens, J.-G. Cuby, F. Mannucci, B. Clément, S. Cristiani, F. Fiore, S. Gallozzi, E. Giallongo, R. Maiolino, N. Menci, A. Moorwood, N. Nonino, A. Renzini, P. Rosati, S. Salimbeni, E. Vanzella Jan 2010

The Bright End Of The Z ~ 7 Uv Luminosity Function From A Wide And Deep Hawk-I Survey, M. Castellano, A. Fontana, D. Paris, A. Grazian, L. Pentericci, K. Boutsia, P. Santini, V. Testa, M. Dickinson, Mauro Giavalisco, R. Bouwens, J.-G. Cuby, F. Mannucci, B. Clément, S. Cristiani, F. Fiore, S. Gallozzi, E. Giallongo, R. Maiolino, N. Menci, A. Moorwood, N. Nonino, A. Renzini, P. Rosati, S. Salimbeni, E. Vanzella

Mauro Giavalisco

(Abridged) We present here the second half of an ESO Large Programme, which exploits the unique combination of area and sensitivity provided in the near-IR by the camera Hawk-I at the VLT. We have obtained - 30 observing hours with Hawk-I in the Y-band of two high galactic latitude fields. We combined the Y-band data with deep J and K Hawk-I observations, and with FORS1/FORS2 U, B, V, R, I, and Z observations to select z-drop galaxies having Z - Y > 1, no optical detection and flat Y - J and Y - K colour terms. We detect 8 high-quality …


A Critical Analysis Of The Uv Luminosity Function At Redshift~7 From Deep Wfc3 Data, A. Grazian, M. Castellano, A. M. Koekemoer, A. Fontana, L. Pentericci, V. Testa, K. Boutsia, E. Giallongo, Mauro Giavalisco, P. Santini Jan 2010

A Critical Analysis Of The Uv Luminosity Function At Redshift~7 From Deep Wfc3 Data, A. Grazian, M. Castellano, A. M. Koekemoer, A. Fontana, L. Pentericci, V. Testa, K. Boutsia, E. Giallongo, Mauro Giavalisco, P. Santini

Mauro Giavalisco

The study of the Luminosity Function (LF) of Lyman Break Galaxies (LBGs) at z=7 is important for ascertaining their role in the reionization of the Universe. We perform a detailed and critical analysis of the statistical and systematic errors in the z~7 LF determination: we have assembled a large sample of candidate LBGs at z~7 from different surveys, spanning a large variety of areas and depths. In particular, we have combined data from the deep (J<27.4) and ultradeep (J<29.2) surveys recently acquired with the new WFC3 NIR camera on HST, over the GOODS-ERS and the HUDF fields, with ground based surveys in wide and shallow areas from VLT and Subaru. We have used public ACS images in the z-band to select z-dropout galaxies, and other public data both in the blue (BVI) and in the red bands to reject possible low-redshift interlopers. We have compared our results with extensive simulations to quantify the observational effects of our selection criteria as well as the effects of photometric scatter, color selections or the morphology of the candidates. We have found that the number density of faint LBGs at z~7 is only marginally sensitive to the color selection adopted, but it is strongly dependent from the assumption made on the half light distributions of the simulated galaxies, used to correct the observed sample for incompleteness. The slope of the faint end of the LBGs LF has thus a rather large uncertainty, due to the unknown distribution of physical sizes of the z~7 LBGs. We conclude that galaxies at z~7 are unable to reionize the Universe unless there is a significant evolution in the clumpiness of the IGM or in the escape fraction of ionising photons or, alternatively, there is a large population of z~7 LBGs with large physical dimensions but still not detected by the present observations.


A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M. Onodera, E. Daddi, R. Gobat, M. Cappellari, N. Arimoto, A. Renzini, Y. Yamada, H. J. Mccracken, C. Mancini, P. Capak, M. Carollo, A. Cimatti, Mauro Giavalisco, O. Ilbert, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi Jan 2010

A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M. Onodera, E. Daddi, R. Gobat, M. Cappellari, N. Arimoto, A. Renzini, Y. Yamada, H. J. Mccracken, C. Mancini, P. Capak, M. Carollo, A. Cimatti, Mauro Giavalisco, O. Ilbert, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi

Mauro Giavalisco

We present observations of a very massive galaxy at z=1.82 which show that its morphology, size, velocity dispersion and stellar population properties that are fully consistent with those expected for passively evolving progenitors of today's giant ellipticals. These findings are based on a deep optical rest-frame spectrum obtained with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru telescope of a high-z passive galaxy candidate (pBzK) from the COSMOS field, for which we accurately measure its redshift of z=1.8230 and obtain an upper limit on its velocity dispersion sigma_star<326 km/s. By detailed stellar population modeling of both the galaxy broad-band SED and the rest-frame optical spectrum we derive a star-formation-weighted age and formation redshift of t_sf~1-2 Gyr and z_form~2.5-4, and a stellar mass of M_star~(3-4)x10^{11} M_sun. This is in agreement with a virial mass limit of M_vir<7x10^{11}M_sun, derived from the measured sigma_star value and stellar half-light radius, as well as with the dynamical mass limit based on the Jeans equations. In contrast with previously reported super-dense passive galaxies at z~2, the present galaxy at z=1.82 appears to have both size and velocity dispersion similar to early-type galaxies in the local Universe with similar stellar mass. This suggests that z~2 massive and passive galaxies may exhibit a wide range of properties, then possibly following quite different evolutionary histories from z~2 to z=0.


A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni Jan 2010

A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni

Mauro Giavalisco

We use the deepest and the most comprehensive photometric data currently available for GOODS-South galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U-band), HST/ACS (F435W, F606W, F775W, and F850LP bands), VLT/ISAAC (J-, H-, and Ks-bands), and four Spitzer/IRAC channels (3.6, 4.5, 5.8, and 8.0 micron). The catalog is selected in the z-band (F850LP) and photometry in each band is carried out using the recently completed TFIT algorithm, which performs PSF matched photometry uniformly across different instruments and filters, despite large variations in PSFs and pixel scales. Photometric redshifts are derived using the GOODZ code, which is based on …


The Rising Star-Formation Histories Of Distant Galaxies And Implications For Gas Accretion With Time, Casey Papovich, Steven L. Finkelstein, Henry C. Ferguson, Jennifer M. Lotz, Mauro Giavalisco Jan 2010

The Rising Star-Formation Histories Of Distant Galaxies And Implications For Gas Accretion With Time, Casey Papovich, Steven L. Finkelstein, Henry C. Ferguson, Jennifer M. Lotz, Mauro Giavalisco

Mauro Giavalisco

Distant galaxies show correlations between their current star-formation rates (SFRs) and stellar masses, implying that their star-formation histories (SFHs) are highly similar. Moreover, observations show that the UV luminosities and stellar masses grow from z=8 to 3, implying that the SFRs increase with time. We compare the cosmologically averaged evolution in galaxies at 3 < z < 8 at constant comoving number density, n = 2 x 10^-4 Mpc^-3. This allows us to study the evolution of stellar mass and star formation in the galaxy predecessors and descendants in ways not possible using galaxies selected at constant stellar mass or SFR, quantities that evolve strongly in time. We show that the average SFH of these galaxies increase smoothly from z=8 to 3 as SFR ~ t^alpha with alpha = 1.7 +/- 0.2. This conflicts with assumptions that the SFR is either constant or declines exponentially in time. We show that the stellar mass growth in these galaxies is consistent with this derived SFH. This provides evidence that the slope of the high-mass end of the IMF is approximately Salpeter unless the duty cycle of star formation is much less than unity. We argue that these relations follow from gas accretion (either through accretion or delivered by mergers) coupled with galaxy disk growth under the assumption that the SFR depends on the local gas surface density. This predicts that gas fractions decrease from z=8 to 3 on average as f_gas ~ (1+z)^0.9 for galaxies with this number density. The implied galaxy gas accretion rates at z > 4 are as fast and may even exceed the SFR: this is the "gas accretion epoch". At z < 4 the SFR overtakes the implied gas accretion rate, indicating a period where galaxies consume gas faster than it is acquired. At z < 3, galaxies with this number density depart from these relations implying that star formation and gas accretion are slowed at later times.


The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati Jan 2010

The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati

Mauro Giavalisco

We use ultra-deep ultraviolet VLT/VIMOS intermediate-band and VLT/FORS1 narrow-band imaging in the GOODS Southern field to derive limits on the distribution of the escape fraction (f_esc) of ionizing radiation for L >~ L*(z=3) Lyman Break Galaxies (LBGs) at redshift 3.4--4.5. Only one LBG, at redshift z=3.795, is detected in its Lyman continuum (LyC; S/N~5.5), the highest redshift galaxy currently known with a direct detection. Its ultraviolet morphology is quite compact (R_eff=0.8, kpc physical). Three out of seven AGN are also detected in their LyC, including one at redshift z=3.951 and z850 = 26.1. From stacked data (LBGs) we set an …


The Relative Abundance Of Compact And Normal Massive Early-Type Galaxies And Its Evolution From Redshift Z~2 To The Present, P. Cassata, Mauro Giavalisco, Yicheng Guo, A. Renzini, H. Ferguson, A. M. Koekemoer, S. Salimbeni, C. Scarlata, N. A. Grogin, C. J. Conselice, T. Dahlen, J. M. Lotz, M. Dickinson, Lihwai Lin Jan 2009

The Relative Abundance Of Compact And Normal Massive Early-Type Galaxies And Its Evolution From Redshift Z~2 To The Present, P. Cassata, Mauro Giavalisco, Yicheng Guo, A. Renzini, H. Ferguson, A. M. Koekemoer, S. Salimbeni, C. Scarlata, N. A. Grogin, C. J. Conselice, T. Dahlen, J. M. Lotz, M. Dickinson, Lihwai Lin

Mauro Giavalisco

We report on the evolution of the number density and size of early-type galaxies from z~2 to z~0. We select a sample of 563 massive (M>10^{10} Msun), passively evolving (SSFR<10^{-2} Gyr^{-1}) and morphologically spheroidal galaxies at 01.2 and z<1.2, respectively). We measure a significant evolution of the mass-size relation of early-type galaxies, with the fractional increment that is almost independent on the stellar mass. Early-type galaxies (ETGs) formed at z>1 appear to be preferentially small, and the evolution of the mass-size relation at z<1 is driven by both the continuous size growth of the compact galaxies and the appearance of new ETGs with large sizes. We also find that the number density of all passive early-type galaxies increases rapidly, by a factor of 5, from z~2 to z~1, and then more mildly by another factor of 1.5 from z~1 to z~0. We interpret these results as the evidence that the bulk of the ETGs are formed at 1