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A Mass Threshold In The Number Density Of Passive Galaxies At Z~2, V. Sommariva, A. Fontana, A. Lamastra, P. Santini, J.S. Dunlop, M. Castellano, H. Ferguson, R.J. Mclure, A. Galametz, Mauro Giavalisco, A Grazian, Y. Lu, N. Menci, A. Merson, D. Paris, L. Pentericci, R. Somerville, T. Targett
A Mass Threshold In The Number Density Of Passive Galaxies At Z~2, V. Sommariva, A. Fontana, A. Lamastra, P. Santini, J.S. Dunlop, M. Castellano, H. Ferguson, R.J. Mclure, A. Galametz, Mauro Giavalisco, A Grazian, Y. Lu, N. Menci, A. Merson, D. Paris, L. Pentericci, R. Somerville, T. Targett
Mauro Giavalisco
The process that quenched star formation in galaxies at intermediate and high redshift is still the subject of considerable debate. One way to investigate this puzzling issue is to study the number density of quiescent galaxies at z ' 2, and its dependence on mass. Here we present the results of a new study based on very deep Ks-band imaging (with the HAWK-I instrument on the VLT) of two HST CANDELS fields (the UKIDSS Ultra-deep survey (UDS) field and GOODS-South). The new HAWK-I data (taken as part of the HUGS VLT Large Program) reach detection limits of Ks > 26 (AB …
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
Stellar Masses From The Candels Survey: The Goods-South And Uds Field, P. Satini, H.C. Ferguson, A Fontana, B. Mobasher, G. Barro, M. Castellano, S.L. Finkelstein, A. Grazian, L.T. Hsu, B. Lee, S.K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M.C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C.J. Conselice, T. Dahlen, M.C. Cooper, Mauro Giavalisco, N.A. Grogin, Y. Guo, N.P. Hathi, D. Kocevski, A.M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J.A. Newman, D. Paris, L. Pentericci, R. Simons, S.P. Willner
Stellar Masses From The Candels Survey: The Goods-South And Uds Field, P. Satini, H.C. Ferguson, A Fontana, B. Mobasher, G. Barro, M. Castellano, S.L. Finkelstein, A. Grazian, L.T. Hsu, B. Lee, S.K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M.C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C.J. Conselice, T. Dahlen, M.C. Cooper, Mauro Giavalisco, N.A. Grogin, Y. Guo, N.P. Hathi, D. Kocevski, A.M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J.A. Newman, D. Paris, L. Pentericci, R. Simons, S.P. Willner
Mauro Giavalisco
We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) project. We combine the effort from ten different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The com- bination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different …
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
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.
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 …
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
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 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 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
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
The Morphology Of Passively Evolving Galaxies At Z ~ 2 From Hst/Wfc3 Deep Imaging In The Hubble Ultradeep Field, P. Cassata, Mauro Giavalisco, Yicheng Guo, H. Ferguson, A. Koekemoer, A. Renzini, A. Fontana, S. Salimbeni, M. Dickinson, S. Casertano, C. J. Conselice, N. Grogin, J. M. Lotz, C. Papovich, R. A. Lucas, A. Straughn, Jonathan P. Gardner, L. Moustakas
The Morphology Of Passively Evolving Galaxies At Z ~ 2 From Hst/Wfc3 Deep Imaging In The Hubble Ultradeep Field, P. Cassata, Mauro Giavalisco, Yicheng Guo, H. Ferguson, A. Koekemoer, A. Renzini, A. Fontana, S. Salimbeni, M. Dickinson, S. Casertano, C. J. Conselice, N. Grogin, J. M. Lotz, C. Papovich, R. A. Lucas, A. Straughn, Jonathan P. Gardner, L. Moustakas
Mauro Giavalisco
We present near-IR images, obtained with the Hubble Space Telescope (HST) and the WFC3/IR camera, of six passive and massive galaxies at redshift 1.3
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broad-Band Photometry, Seong-Kook Lee, Rafal Idzi, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broad-Band Photometry, Seong-Kook Lee, Rafal Idzi, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Mauro Giavalisco
We investigate the biases and uncertainties in estimates of physical parameters of high-redshift Lyman break galaxies (LBGs), such as stellar mass, mean stellar population age, and star formation rate (SFR), obtained from broad-band photometry. By combining LCDM hierarchical structure formation theory, semi-analytic treatments of baryonic physics, and stellar population synthesis models, we construct model galaxy catalogs from which we select LBGs at redshifts z ~ 3.4, 4.0, and 5.0. The broad-band spectral energy distributions (SEDs) of these model LBGs are then analysed by fitting galaxy template SEDs derived from stellar population synthesis models with smoothly declining SFRs. We compare the …