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Full-Text Articles in Physical Sciences and Mathematics
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
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 …
Characterizing Faint Galaxies In The Reionization Epoch: Lbt Confirms Two L < 0.2l Sources At Z = 6.4 Behind The Clash/Frontier Fields Cluster Macs0717.5+3745, E. Vanzella, A. Fontana, A. Zitrin, E. Coe, L. Bradley, M. Postman, A. Grazian, M. Castellano, L. Pentericci, Mauro Giavalisco, P. Rosati, M. Nonino, R. Smit, L. Balestra, R. Bouwens, S. Cristiani, E. Giallongo, W. Zheng, L. Infante, F. Cusano, R. Speziali
Characterizing Faint Galaxies In The Reionization Epoch: Lbt Confirms Two L < 0.2l Sources At Z = 6.4 Behind The Clash/Frontier Fields Cluster Macs0717.5+3745, E. Vanzella, A. Fontana, A. Zitrin, E. Coe, L. Bradley, M. Postman, A. Grazian, M. Castellano, L. Pentericci, Mauro Giavalisco, P. Rosati, M. Nonino, R. Smit, L. Balestra, R. Bouwens, S. Cristiani, E. Giallongo, W. Zheng, L. Infante, F. Cusano, R. Speziali
Mauro Giavalisco
We report the LBT/MODS1 spectroscopic confirmation of two images of faint Lyman alpha emitters at z = 6.4 behind the Frontier Fields galaxy cluster MACSJ0717.5+3745. A wide range of lens models suggests that the two images are highly magnified, with a strong lower limit of μ > 5. These are the faintest z > 6 candidates spectroscopically confirmed to date. These may be also multiple images of the same z = 6.4 source as supported by their similar intrinsic properties, but the lens models are inconclusive regarding this interpretation. To be cautious, we derive the physical properties of each image individually. Thanks …
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
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
Star Formation And Stellar Mass Assembly In Dark Matter Halos: From Giants To Dwarfs, Zhankui Lu, H.J. Mo, Yu Lu, Neal S. Katz, Martin D. Weinberg, Frank C. Van Den Bosch, Xiaohu Yang
Star Formation And Stellar Mass Assembly In Dark Matter Halos: From Giants To Dwarfs, Zhankui Lu, H.J. Mo, Yu Lu, Neal S. Katz, Martin D. Weinberg, Frank C. Van Den Bosch, Xiaohu Yang
Neal S. Katz
The empirical model of Lu et al. is updated with recent data of galaxy stellar mass functions (SMFs). The model predicts that the slope of galaxy SMFs at z > 2 should be quite steep at the low-mass end, beyond the current detection limit, and it is a strong prediction that can be tested against future observations. The model is used to investigate the galaxy star formation and assembly or merger histories in detail. Most of the stars in cluster centrals, corresponding to brightest cluster galaxies in observations, formed earlier than z ≈ 2 but have been assembled much later. Typically, …
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
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 …
Bayesian Inferences Of Galaxy Formation From The K-Band Luminosity And Hi Mass Functions Of Galaxies: Constraining Star Formation And Feedback, Yu Lu, H.J. Mo, Zhankui Lu, Neal S. Katz, Martin D. Weinberg
Bayesian Inferences Of Galaxy Formation From The K-Band Luminosity And Hi Mass Functions Of Galaxies: Constraining Star Formation And Feedback, Yu Lu, H.J. Mo, Zhankui Lu, Neal S. Katz, Martin D. Weinberg
Neal S. Katz
We infer mechanisms of galaxy formation for a broad family of semi-analytic models (SAMs) constrained by the K-band luminosity function and H I mass function of local galaxies using tools of Bayesian analysis. Even with a broad search in parameter space the whole model family fails to match to constraining data. In the best-fitting models, the star formation and feedback parameters in low-mass haloes are tightly constrained by the two data sets, and the analysis reveals several generic failures of models that similarly apply to other existing SAMs. First, based on the assumption that baryon accretion follows the dark matter …
A 52 Hours Vlt/Fors2 Spectrum Of A Bright Z ~ 7 Hudf Galaxy: No Lya Emission, E. Venzella, A. Fontana, L. Pentericci, M. Castellano, A. Grazian, Mauro Giavalisco, M. Nonino, S. Cristiani, G. Zamorani, C. Vignali
A 52 Hours Vlt/Fors2 Spectrum Of A Bright Z ~ 7 Hudf Galaxy: No Lya Emission, E. Venzella, A. Fontana, L. Pentericci, M. Castellano, A. Grazian, Mauro Giavalisco, M. Nonino, S. Cristiani, G. Zamorani, C. Vignali
Mauro Giavalisco
Aims: We aim to determine the redshift of GDS_1408, the most solid z _ 7 galaxy candidate lying in the Hubble Ultra Deep Field. Methods: We have used all the VLT spectra of GDS_1408 collected by us and two other groups with FORS2 at VLT in the last five years, for a total integration time of 52hr. The combined spectrum is the deepest ever obtained of a galaxy in the Reionization epoch. Results: We do not detect any emission line or continuum over the whole wavelength range, up to 10100Å. Based on an accurate set of simulations, we are able …
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
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 Cos-Halos Survey: Physical Conditions And Baryonic Mass In The Low-Redshift Circumgalactic Medium, Jessica K. Werk, J. Xavier Prochaska, Jason Tumlinson, Molly S. Peeples, Todd M. Tripp, Andrew J. Fox, Nicolas Lehner, Christopher Thom, John M. O'Meara, Amanda Brady Ford, Rongmon Bordoloi, Neal S. Katz, Nicolas Tejos, Benjamin D. Oppenheimer, Romeel Dave, David H. Weinberg
The Cos-Halos Survey: Physical Conditions And Baryonic Mass In The Low-Redshift Circumgalactic Medium, Jessica K. Werk, J. Xavier Prochaska, Jason Tumlinson, Molly S. Peeples, Todd M. Tripp, Andrew J. Fox, Nicolas Lehner, Christopher Thom, John M. O'Meara, Amanda Brady Ford, Rongmon Bordoloi, Neal S. Katz, Nicolas Tejos, Benjamin D. Oppenheimer, Romeel Dave, David H. Weinberg
Neal S. Katz
We analyze the physical conditions of the cool, photoionized (T ~104 K) circumgalactic medium (CGM) using the COS-Halos suite of gas column density measurements for 44 gaseous halos within 160 kpc of L ~ L* galaxies at z ~ 0.2. These data are well described by simple photoionization models, with the gas highly ionized (n H II /n H gsim 99%) by the extragalactic ultraviolet background. Scaling by estimates for the virial radius, R vir, we show that the ionization state (tracked by the dimensionless ionization parameter, U) increases with distance from the host galaxy. The ionization parameters imply a …
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
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 Neutral Hydrogen Content Of Galaxies In Cosmological Hydrodynamic Simulations, Romeel Dave, Neal S. Katz, Benjamin D. Oppenheimer, Juna A. Kollmeier, David H. Weinberg
The Neutral Hydrogen Content Of Galaxies In Cosmological Hydrodynamic Simulations, Romeel Dave, Neal S. Katz, Benjamin D. Oppenheimer, Juna A. Kollmeier, David H. Weinberg
Neal S. Katz
We examine the global H I properties of galaxies in quarter billion particle cosmological simulations using GADGET-2, focusing on how galactic outflows impact H I content. We consider four outflow models, including a new one (ezw) motivated by recent interstellar medium simulations in which the wind speed and mass loading factor scale as expected for momentum-driven outflows for larger galaxies and energy-driven outflows for dwarfs (σ < 75 km s−1). To obtain predicted H I masses, we employ a simple but effective local correction for particle self-shielding and an observationally constrained transition from neutral to molecular hydrogen. Our ezw simulation produces an H I mass function whose faint-end slope of −1.3 agrees well with observations from the Arecibo Fast Legacy ALFA survey; other models agree less well. Satellite galaxies have a bimodal distribution in H I fraction versus halo mass, with smaller satellites and/or those in larger haloes more often being H I deficient. At a given stellar mass, H I content correlates with the star formation rate and inversely correlates with metallicity, as expected if driven by stochasticity in the accretion rate. To higher redshifts, massive H I galaxies disappear and the mass function steepens. The global cosmic H I density conspires to remain fairly constant from z ∼ 5 → 0, but the relative contribution from smaller galaxies increases with redshift.
The Assembly Of Galaxies Over Cosmic Time, Yicheng Guo
The Assembly Of Galaxies Over Cosmic Time, Yicheng Guo
Open Access Dissertations
To Understand how galaxies were assembled across the cosmic time remains one of the most outstanding questions in astronomy. The core of this question is how today's Hubble Sequence, namely the differentiation of galaxy morphology and its correlation to galaxy physical properties, is formed. In this thesis, we investigate the origin of the Hubble Sequence through galaxies at z~2, an epoch when the cosmic star formation activity reaches its peak and the properties of galaxies undergo dramatic transitions. Galaxies at z~2 have two important features that are distinct from nearby galaxies: much higher frequency of clumpy morphology in star-forming systems, …
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
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
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
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 …
On The Detection Of Ionizing Radiation Arising From Star-Forming Galaxies At Redshift Z ~ 3-4 : Looking For Analogs Of "Stellar Reionizers", Eros Vanzella, Yicheng Guo, Mauro Giavalisco, Andrea Grazian, Marco Castellano, Stefano Cristiani, Mark Dickinson, Adriano Fontana, Mario Nonino, Emanuele Giallongo, Laura Pentericci, Audrey Galametz, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Anton M. Koekemoer, Jeffrey Newman, Brian D. Siana
On The Detection Of Ionizing Radiation Arising From Star-Forming Galaxies At Redshift Z ~ 3-4 : Looking For Analogs Of "Stellar Reionizers", Eros Vanzella, Yicheng Guo, Mauro Giavalisco, Andrea Grazian, Marco Castellano, Stefano Cristiani, Mark Dickinson, Adriano Fontana, Mario Nonino, Emanuele Giallongo, Laura Pentericci, Audrey Galametz, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Anton M. Koekemoer, Jeffrey Newman, Brian D. Siana
Mauro Giavalisco
We use the spatially-resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z~3.7 identified using ultra-deep imaging below the Lyman limit (1-sigma limit of ~30 AB in a 2" diameter aperture). In 18 candidates, out of a sample of 19 with flux detected at >3-sigma level, the light centroid of the candidate LyC emission is offset from that of the LBG by up to 1.5". We fit the SED of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the …
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
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 …
Modeling The Effects Of Star Formation Histories On Halpha And Ultra-Violet Fluxes In Nearby Dwarf Galaxies, Daniel R. Weisz, Benjamin D. Johnson, L. Clifton Johnson, Evan D. Skillman, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Liese Van Zee, Matthew S. Bothwell, Julianne J. Dalcanton, Daniel A. Dale, Benjamin F. Williams
Modeling The Effects Of Star Formation Histories On Halpha And Ultra-Violet Fluxes In Nearby Dwarf Galaxies, Daniel R. Weisz, Benjamin D. Johnson, L. Clifton Johnson, Evan D. Skillman, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Liese Van Zee, Matthew S. Bothwell, Julianne J. Dalcanton, Daniel A. Dale, Benjamin F. Williams
Daniela Calzetti
We consider the effects of non-constant star formation histories (SFHs) on Halpha and GALEX far ultra-violet (FUV) star formation rate (SFR) indicators. Under the assumption of a fully populated Chabrier IMF, we compare the distribution of Halpha-to-FUV flux ratios from ~ 1500 simple, periodic model SFHs with observations of 185 galaxies from the Spitzer Local Volume Legacy survey. We find a set of SFH models that are well matched to the data, such that more massive galaxies are best characterized by nearly constant SFHs, while low mass systems experience bursts amplitudes of ~ 30 (i.e., an increase in the SFR …
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
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 …
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, Hj Mccracken, C Mancini, P Capak, M Carollo, A Cimatti, M Giavalisco, O Ilbert, X Kong, S Lilly, K Motohara, K Ohta, Db Sanders, N Scoville, N Tamura, Y Taniguchi
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, Hj Mccracken, C Mancini, P Capak, M Carollo, A Cimatti, M Giavalisco, O Ilbert, X Kong, S Lilly, K Motohara, K Ohta, Db Sanders, N Scoville, N Tamura, Y Taniguchi
Astronomy Department Faculty Publication Series
We present observations of a very massive galaxy at z = 1.82 that show that its morphology, size, velocity dispersion, and stellar population properties 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 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 σ⋆ < 326 km s−1. By detailed stellar population modeling of both the galaxy broadband spectral energy distribution and the rest-frame optical spectrum, we derive a star formation-weighted age and formation redshift of tsf ≃ 1–2 Gyr and z …
The Nature Of Submillimetre Galaxies In Cosmological Hydrodynamic Simulations, R Dave, K Finlator, Bd Oppenheimer, M Fardal, N Katz, D Keres, Dh Weinberg
The Nature Of Submillimetre Galaxies In Cosmological Hydrodynamic Simulations, R Dave, K Finlator, Bd Oppenheimer, M Fardal, N Katz, D Keres, Dh Weinberg
Astronomy Department Faculty Publication Series
We study the nature of rapidly star-forming galaxies at z= 2 in cosmological hydrodynamic simulations, and compare their properties to observations of submillimetre galaxies (SMGs). We identify simulated SMGs as the most rapidly star-forming systems that match the observed number density of SMGs. In our models, SMGs are massive galaxies sitting at the centres of large potential wells, being fed by smooth infall and gas-rich satellites at rates comparable to their star formation rates (SFRs). They are not typically undergoing major mergers that significantly boost their quiescent SFR, but they still often show complex gas morphologies and kinematics. Our …
Ly Alpha Emission From Cosmic Structure. I. Fluorescence, Ja Kollmeier, Z Zheng, R Dave, A Gould, N Katz, J Miralda-Escude, Dh Weinberg
Ly Alpha Emission From Cosmic Structure. I. Fluorescence, Ja Kollmeier, Z Zheng, R Dave, A Gould, N Katz, J Miralda-Escude, Dh Weinberg
Astronomy Department Faculty Publication Series
We present predictions for the fluorescent Lyα emission signature arising from photoionized, optically thick structures in smoothed particle hydrodynamic cosmological simulations of a ΛCDM universe using a Monte Carlo Lyα radiative transfer code. We calculate the expected Lyα image and two-dimensional spectra for gas exposed to a uniform ultraviolet ionizing background as well as gas exposed additionally to the photoionizing radiation from a local quasar, after correcting for the self-shielding of hydrogen. As a test of our numerical methods and for application to current observations, we examine simplified analytic structures that are uniformly or anisotropically illuminated. We compare these results …
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
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.
Spectroscopic Confirmation Of Z~7 Lbgs: Probing The Earliest Galaxies And The Epoch Of Reionization, L. Pentericci, A. Fontana, E. Vanzella, M. Castellano, A. Grazian, M. Dijkstra, K. Boustia, S. Cristiani, M. Dickinson, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, P. Santini
Spectroscopic Confirmation Of Z~7 Lbgs: Probing The Earliest Galaxies And The Epoch Of Reionization, L. Pentericci, A. Fontana, E. Vanzella, M. Castellano, A. Grazian, M. Dijkstra, K. Boustia, S. Cristiani, M. Dickinson, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, P. Santini
Mauro Giavalisco
We present the final results from our ultra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z~7 "z--band dropout" candidates selected from our VLT/Hawk-I imaging survey over three independent fields. In particular we report on two newly discovered galaxies at redshift ~6.7 in the NTT deep field: both galaxies show a Ly-alpha emission line with rest-frame EWs of the order 15-20 A and luminosities of 2-4 X 10^{42} erg/s. We also present the results of ultra-deep observations of a sample of i-dropout galaxies, from which we set a solid upper limit on the fraction of interlopers. Out …
The Lack Of Intense Lyman~Alpha In Ultradeep Spectra Of Z=7 Candidates In Goods-S: Imprint Of Reionization?, A. Fontana, E. Vanzella, L. Pentericci, M. Castellano, Mauro Giavalisco, A. Grazian, K. Boutsia, S. Christiani, M. Dickinson, E. Giallongo, M. Maiolino, A. Moorwood, P. Santini
The Lack Of Intense Lyman~Alpha In Ultradeep Spectra Of Z=7 Candidates In Goods-S: Imprint Of Reionization?, A. Fontana, E. Vanzella, L. Pentericci, M. Castellano, Mauro Giavalisco, A. Grazian, K. Boutsia, S. Christiani, M. Dickinson, E. Giallongo, M. Maiolino, A. Moorwood, P. Santini
Mauro Giavalisco
We present ultradeep optical spectroscopy obtained with FORS2 on VLT of seven Lyman-break galaxy (LBG) candidates at z>6.5 selected in the GOODS-S field from Hawk-I/VLT and WFC3/HST imaging. For one galaxy we detect a low significance emission line (S/N< 7), located at 9691.5 +/- 0.5A and with flux 3.4 x 10^(-18)erg/cm^2/s. If identified as Lyman alpha, it places the LBG at redshift z=6.972+/- 0.002, with a rest-frame equivalent width EW}=13A. Using Monte Carlo simulations and conservative EW distribution functions at 210 is ~ 2%, and that of observing only one galaxy out of seven with S/N=5 is ~4%, but these can be as small as ~1E-3, depending on the details of the EW distribution. We conclude that either a significant fraction of the candidates is not at high redshift or that some physical mechanism quenches the Lyman alpha emission emerging from the galaxies at z>6.5, abruptly reversing the trend of the increasing fraction of strong emitters with increasing redshift observed up to z~ 6.5. We discuss the possibility that an increasingly neutral intergalactic medium is responsible for such quenching.
Spectroscopic Confirmation Of Two Lyman Break Galaxies At Redshift Beyond 7, E. Vanzella, L. Pentericci, A. Fontana, A. Grazian, M. Castellano, K. Boutsia, S. Cristiani, M. Dickinson, S. Gallozzi, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, D. Paris, P. Santini
Spectroscopic Confirmation Of Two Lyman Break Galaxies At Redshift Beyond 7, E. Vanzella, L. Pentericci, A. Fontana, A. Grazian, M. Castellano, K. Boutsia, S. Cristiani, M. Dickinson, S. Gallozzi, E. Giallongo, Mauro Giavalisco, R. Maiolino, A. Moorwood, D. Paris, P. Santini
Mauro Giavalisco
We report the spectroscopic confirmation of two Lyman break galaxies at redshift > 7. The galaxies were observed as part of an ultra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z~7 ``z--band dropout'' candidates selected from our VLT/Hawk-I imaging survey. Both galaxies show a prominent emission line at 9735A and 9858A respectively: the lines have fluxes of ~ 1.6-1.2 x 10^(-17) erg/s/cm2 and exhibit a sharp decline on the blue side and a tail on the red side. The asymmetry is quantitatively comparable to the observed asymmetry in z ~ 6 Ly-alpha lines, where absorption by neutral …
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
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
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 Unusual N Iv]-Emitter Galaxy Gds J033218.92-275302.7: Star Formation Or Agn-Driven Winds From A Massive Galaxy At Z=5.56, E Vanzella, A Grazian, M Hayes, L Pentericci, D Schaerer, M Dickinson, S Cristiani, M Giavalisco, A Verhamme, M Nonino, P Rosati
The Unusual N Iv]-Emitter Galaxy Gds J033218.92-275302.7: Star Formation Or Agn-Driven Winds From A Massive Galaxy At Z=5.56, E Vanzella, A Grazian, M Hayes, L Pentericci, D Schaerer, M Dickinson, S Cristiani, M Giavalisco, A Verhamme, M Nonino, P Rosati
Astronomy Department Faculty Publication Series
Aims. We investigate the nature of the source GDS J033218.92-275302.7 at redshift 5.56.
Methods. The spectral energy distribution of the source is well-sampled by 16 bands photometry from UV-optical (HST and VLT), near infrared, near infrared (VLT) to mid-infrared (Spitzer). The detection of a signal in the mid-infrared Spitzer/IRAC bands 5.8, 8.0 - where the nebular emission contribution is less effective - suggests that there is a Balmer break, the signature of an underlying stellar population formed at earlier epochs. The high-quality VLT/FORS2 spectrum shows a clear Ly emission line, together with semi-forbidden N IV] 1483.3-1486.5 also …
Structural Properties Of Central Galaxies In Groups And Clusters, Yc Guo, Dh Mcintosh, Hj Mo, N Katz, Fc Van Den Bosch, M Weinberg, Sm Weinmann, A Pasquali, Xh Yang
Structural Properties Of Central Galaxies In Groups And Clusters, Yc Guo, Dh Mcintosh, Hj Mo, N Katz, Fc Van Den Bosch, M Weinberg, Sm Weinmann, A Pasquali, Xh Yang
Astronomy Department Faculty Publication Series
Using a statistically representative sample of 911 central galaxies (CENs) from the Sloan Digital Sky Survey (SDSS) Data Release 4 group catalogue, we study how the structure (shape and size) of the first rank (by stellar mass) group and cluster members depends on (1) galaxy stellar mass (Mstar), (2) the global environment defined by the dark matter halo mass (Mhalo) of the host group and (3) the local environment defined by their special halocentric position. We quantify the structure of SDSS galaxies with a galfit-based pipeline that fits two-dimensional Sérsic models to the r-band image data. Through tests with simulated …