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Articles 1 - 16 of 16
Full-Text Articles in Astrophysics and Astronomy
Morphology And Environment Of Galaxies With Disc Breaks In The S4g And Nirs0s, J. Laine, E. Laurikainen, H. Salo, S. Comeron, R. J. Buta, D. Zaritsky, E. Athanassoula, A. Bosma, J.-C. Munoz-Mateos, D. A. Gadotti, J. L. Hinz, S. Erroz-Ferrer, A. Gil De Paz, T. Kim, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, M. Seibert, K. Sheth
Morphology And Environment Of Galaxies With Disc Breaks In The S4g And Nirs0s, J. Laine, E. Laurikainen, H. Salo, S. Comeron, R. J. Buta, D. Zaritsky, E. Athanassoula, A. Bosma, J.-C. Munoz-Mateos, D. A. Gadotti, J. L. Hinz, S. Erroz-Ferrer, A. Gil De Paz, T. Kim, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, M. Seibert, K. Sheth
Aerospace, Physics, and Space Science Faculty Publications
We study the surface brightness profiles of disc galaxies in the 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies (S4G) and Ks-band images from the Near-Infrared S0-Sa galaxy Survey (NIRS0S). We particularly connect properties of single exponential (type I), downbending double exponential (type II), and upbending double exponential (type III) disc profile types, to structural components of galaxies by using detailed morphological classifications, and size measurements of rings and lenses. We also study how the local environment of the galaxies affects the profile types by calculating parameters describing the environmental density and the tidal …
The Baryonic Tully-Fisher Relationship For S4g Galaxies And The "Condensed" Baryon Fraction Of Galaxies., Dennis Zaritsky, Helene M. Courtois, Juan Carlos Munoz-Mateos, Jenny Sorce, S. Erroz-Ferrer, S. Comeron, D. A. Gadotti, A. Gil De Paz, J. L. Hinz, E. Laurikainen, T. Kim, J. Laine, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, H. Salo, M. Seibert, K. Sheth, E. Athanassoula, A. Bosma, M. Cisternas, Luis C. Ho, Benne W. Holwerda
The Baryonic Tully-Fisher Relationship For S4g Galaxies And The "Condensed" Baryon Fraction Of Galaxies., Dennis Zaritsky, Helene M. Courtois, Juan Carlos Munoz-Mateos, Jenny Sorce, S. Erroz-Ferrer, S. Comeron, D. A. Gadotti, A. Gil De Paz, J. L. Hinz, E. Laurikainen, T. Kim, J. Laine, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, H. Salo, M. Seibert, K. Sheth, E. Athanassoula, A. Bosma, M. Cisternas, Luis C. Ho, Benne W. Holwerda
Faculty Scholarship
We combine data from the Spitzer Survey for Stellar Structure in Galaxies, a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of H i spectral line profiles to examine the baryonic Tully–Fisher (BTF) relation. We find (1) that the BTF has lower scatter than the classic Tully–Fisher (TF) relation and is better described as a linear relationship, confirming similar previous results, (2) that the inclusion of a radial scale in the BTF decreases the scatter but only modestly, as seen previously for the TF relation, and (3) that the slope of the BTF, which …
The Luminosity Function At Z ~ 8 From 97 Y-Band Dropouts : Inferences About Reionization., Kasper B. Schmidt, Tommaso Treu, Michele Trenti, Larry D. Bradley, Brandon C. Kelly, Pascal A. Oesch, Benne W. Holwerda, J. Michael Shull, Massimo Stiavelli
The Luminosity Function At Z ~ 8 From 97 Y-Band Dropouts : Inferences About Reionization., Kasper B. Schmidt, Tommaso Treu, Michele Trenti, Larry D. Bradley, Brandon C. Kelly, Pascal A. Oesch, Benne W. Holwerda, J. Michael Shull, Massimo Stiavelli
Faculty Scholarship
We present the largest search to date for Y-band dropout galaxies (z ∼ 8 Lyman break galaxies, LBGs) based on 350 arcmin2 of Hubble Space Telescope observations in the V, Y, J, and H bands from the Brightest of Reionizing Galaxies (BoRG) survey. In addition to previously published data, the BoRG13 data set presented here includes approximately 50 arcmin2 of new data and deeper observations of two previous BoRG pointings, from which we present 9 new z ∼ 8 LBG candidates, bringing the total number of BoRG Y-band dropouts to 38 with 25.5 mJ 27.6 (AB system). We introduce 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
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 …
Unveiling The Structure Of Barred Galaxies At 3.6 Μm With The Spitzer Survey Of Stellar Structure In Galaxies (S4g). I. Disk Breaks., Taehyun Kim, Dimitri A. Gadotti, Kartik Sheth, E. Athanassoula, Albert Bosma, Myung Gyoon Lee, Barry F. Madore, Bruce G. Elmegreen, Johan H. Knapen, Dennis Zaritsky, Luis C. Ho, Sebastien Comeron, Benne W. Holwerda, Joannah L. Hinz, Juan Carlos Munoz-Mateos, Mauricio Cisternas, Santiago Erroz-Ferrer, Ron Buta, Eija Laurikainen, Heikki Salo, Jarkko Laine, Karin Menendez-Delmestre, Michael W. Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
Unveiling The Structure Of Barred Galaxies At 3.6 Μm With The Spitzer Survey Of Stellar Structure In Galaxies (S4g). I. Disk Breaks., Taehyun Kim, Dimitri A. Gadotti, Kartik Sheth, E. Athanassoula, Albert Bosma, Myung Gyoon Lee, Barry F. Madore, Bruce G. Elmegreen, Johan H. Knapen, Dennis Zaritsky, Luis C. Ho, Sebastien Comeron, Benne W. Holwerda, Joannah L. Hinz, Juan Carlos Munoz-Mateos, Mauricio Cisternas, Santiago Erroz-Ferrer, Ron Buta, Eija Laurikainen, Heikki Salo, Jarkko Laine, Karin Menendez-Delmestre, Michael W. Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
Faculty Scholarship
We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the disk break and using a single disk scale length in the model fit for Type II (down-bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We find that for galaxies …
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.
Constraining The Age Of The Ngc 4565 Hi Disk Warp : Determining The Origin Of Gas Warps., David J. Radburn-Smith, Roelof S. De Jong, David Streich, Eric F. Bell, Julianne J. Dalcanton, Andrew E. Dolphin, Adrienne M. Stilp, Antonela Monachesi, Benne W. Holwerda, Jeremy Bailin
Constraining The Age Of The Ngc 4565 Hi Disk Warp : Determining The Origin Of Gas Warps., David J. Radburn-Smith, Roelof S. De Jong, David Streich, Eric F. Bell, Julianne J. Dalcanton, Andrew E. Dolphin, Adrienne M. Stilp, Antonela Monachesi, Benne W. Holwerda, Jeremy Bailin
Faculty Scholarship
We have mapped the distribution of young and old stars in the gaseous H i warp of NGC 4565. We find a clear correlation of young stars (< 600 Myr) with the warp but no coincident old stars (> 1 Gyr), which places an upper limit on the age of the structure. The formation rate of the young stars, which increased ∼ 300 Myr ago relative to the surrounding regions, is (6.3+2.5 −1.5) × 10−5 M yr−1 kpc−2. This implies a ∼ 60 ± 20 Gyr depletion time of the H i warp, similar to the timescales calculated for the outer H i disks of nearby spiral galaxies. While some stars …