Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

PDF

University of Massachusetts Amherst

2014

Articles 1 - 30 of 55

Full-Text Articles in Physical Sciences and Mathematics

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 …

Go to article

Chemical Potential In The First Law For Holographic Entanglement Entropy, David Kastor, Sourya Ray, Jennie Traschen Nov 2014

Chemical Potential In The First Law For Holographic Entanglement Entropy, David Kastor, Sourya Ray, Jennie Traschen

David Kastor

Entanglement entropy in conformal field theories is known to satisfy a first law. For spherical entangling surfaces, this has been shown to follow via the AdS/CFT correspondence and the holographic prescription for entanglement entropy from the bulk first law for Killing horizons. The bulk first law can be extended to include variations in the cosmological constant Λ, which we established in earlier work. Here we show that this implies an extension of the boundary first law to include varying the number of degrees of freedom of the boundary CFT. The thermodynamic potential conjugate to Λ in the bulk is called …

Go to article

Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy, Sebastian Fischetti, David Kastor, Jennie Traschen Nov 2014

Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy, Sebastian Fischetti, David Kastor, Jennie Traschen

David Kastor

We extend standard results for vacuum asymptotically locally AdS (AlAdS) spacetimes, showing that such spacetimes can be constructed as foliations where the induced metric on each hypersurface satisfies Einstein's equation with stress-energy. By an appropriate choice of stress-energy on the hypersurfaces, the resulting AlAdS spacetime satisfies Einstein's equation with a negative cosmological constant and physical stress tensor. We use this construction to obtain AlAdS solutions whose boundaries are FRW cosmologies sourced by a massless scalar field or by a perfect fluid obeying the strong energy condition. We focus on FRW universes that approach Minkowski spacetime at late times, yielding AlAdS …

Go to article

On The Formation And Evolution Of Early-Type Galaxies, Christina Williams Nov 2014

On The Formation And Evolution Of Early-Type Galaxies, Christina Williams

Doctoral Dissertations

Galaxies in the local Universe are characterized by blue, star-forming disk galaxies, and red, massive early-type galaxies (ETGs) whose star-formation has been quenched early in the Universe's history. The ETGs are relics of the evolutionary processes that transform galaxies over cosmic time, but currently we still lack a comprehensive understanding of their evolution. An important link in the evolution of ETGs is that the first quenched galaxies (z~2) are both the most massive, and most compact, suggesting a physical connection between high stellar density and efficient, rapid cessation of star-formation. In this dissertation, I seek insight into the formation and …

Go to article

Dusty Star Formation In Extreme Environments: Galaxies And Galaxy Clusters In The Distant Universe, Stacey Alberts Nov 2014

Dusty Star Formation In Extreme Environments: Galaxies And Galaxy Clusters In The Distant Universe, Stacey Alberts

Doctoral Dissertations

In this thesis, we present a comprehensive study of the dust-obscured star formation (SF) activity in galaxy clusters out to high redshift using infrared (IR) imaging. Using hundreds of galaxy clusters and wide-field far-IR imaging across nine square degrees, we quantify the average star formation rates (SFRs) out to the distant Universe for mass-limited cluster galaxy samples using stacking. We compare the evolution of this SF activity to field galaxies, finding that the evolution in clusters occurs more rapidly than in the field and clusters have field-like SF approximately nine billion years ago, during an epoch before SF quenching becomes …

Go to article

A Spitzer View Of The Giant Molecular Cloud Mon Ob1/Ngc 2264, Valerie A. Rapson, Judith L. Pipher, R. A. Gutermuth, Megeatj S. Thomas, Thomas S. Allen, Phillip C. Myers, Lori E. Allen Oct 2014

A Spitzer View Of The Giant Molecular Cloud Mon Ob1/Ngc 2264, Valerie A. Rapson, Judith L. Pipher, R. A. Gutermuth, Megeatj S. Thomas, Thomas S. Allen, Phillip C. Myers, Lori E. Allen

Robert A. Gutermuth

We present Spitzer 3.6, 4.5, 5.8, 8.0, and 24 μm images of the Mon OB1 East giant molecular cloud, which contains the young star forming region NGC 2264, as well as more extended star formation. With Spitzer data and Two Micron All Sky Survey photometry, we identify and classify young stellar objects (YSOs) with dusty circumstellar disks and/or envelopes in Mon OB1 East by their infrared-excess emission and study their distribution with respect to cloud material. We find a correlation between the local surface density of YSOs and column density of molecular gas as traced by dust extinction that is …

Go to article

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 Sep 2014

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 …

Go to article

Rapid Decline Of Lyman-Α Emission Toward The Reionization Era, V. Tilvi, C. Papovich, H.C. Ferguson, S.L. Finkelstein, J. Long, M. Song, M. Dickinson, A.M. Koekemoer, Mauro Giavalisco, B. Mobasher Sep 2014

Rapid Decline Of Lyman-Α Emission Toward The Reionization Era, V. Tilvi, C. Papovich, H.C. Ferguson, S.L. Finkelstein, J. Long, M. Song, M. Dickinson, A.M. Koekemoer, Mauro Giavalisco, B. Mobasher

Mauro Giavalisco

The observed deficit of strongly Lyman-α emitting galaxies at z > 6.5 is attributed to either increasing neutral hydrogen in the intergalactic medium (IGM) and/or to the evolving galaxy properties. To investigate this, we have performed very deep near-IR spectroscopy of z ≳7 galaxies using MOSFIRE on the Keck-I Telescope. We measure the Lyman-α fraction at z ∼ 8 using two methods. First, we derived NLy_/Ntot directly using extensive simulations to correct for incompleteness. Second, we used a Bayesian formalism (introduced by Treu et al. 2012) that compares the z > 7 galaxy spectra to models of the Lyman-α equivalent width (WLy_) …

Go to article

Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, Keith Otis Aug 2014

Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, Keith Otis

Doctoral Dissertations

This dissertation presents the first direct detection of pp solar neutrinos within Borexino, the underground liquid-scintilator detector located at the Gran Sasso National Labratory(LNGS) in Italy, designed to measure the interaction of neutrinos through neutrino-electron elastic scattering. The rate of scattering in Borexino from the pp solar neutrino spectrum is measured to be 155 +/- 16(stat) +/- 13(sys) counts per day per 100 tonnes. With this measurement we are able to rule out the no oscillation hypothesis at the 2-sigma C.L. and the results agree with Standard Solar Model predictions within 1.1-sigma. These neutrinos are from the keystone proton-proton fusion …

Go to article

Measures Of Star Formation Rates Within Galaxies: The Impact Of Diffuse Stellar Populations, Yiming Li Aug 2014

Measures Of Star Formation Rates Within Galaxies: The Impact Of Diffuse Stellar Populations, Yiming Li

Doctoral Dissertations

Thanks to the Spitzer Space Telescope, the infrared (IR) emission have been better studied in the past decades, as well as its relations to star formation rates (SFR) and the calibrations of IR emissions as SFR indicators. However, the far infrared (FIR) emission are still understudied, especially at the sub-galactic region scales. In this dissertation, I present new ground--based observations in the light of the infrared hydrogen recombination line Br[gamma] (2.16~mu m) of a sample of KINGFISH (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel) galaxies. The Br[gamma] emission line offers the double advantage of directly tracing ionizing …

Go to article

Magnetic Fields In An Expanding Universe, David Kastor, Jennie Traschen Mar 2014

Magnetic Fields In An Expanding Universe, David Kastor, Jennie Traschen

David Kastor

We find a solution to 4D Einstein-Maxwell theory coupled to a massless dilaton field describing a Melvin magnetic field in an expanding universe with 'stiff matter' equation of state parameter w=+1. As the universe expands, magnetic flux becomes more concentrated around the symmetry axis for dilaton coupling a<1/3√ and more dispersed for a>1/3√. An electric field circulates around the symmetry axis in the direction determined by Lenz's law. For a=0 the magnetic flux through a disk of fixed comoving radius is proportional to the proper area of the disk. This result disagrees with the usual expectation based on a test magnetic field that this …

Go to article

Steadily Increasing Star Formation Rates In Galaxies Observed At 3≲Zv5 In The Candels/Goods-S Field, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Mauro Giavalisco, Tommy Wiklind, Tomas Dahlen Feb 2014

Steadily Increasing Star Formation Rates In Galaxies Observed At 3≲Zv5 In The Candels/Goods-S Field, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Mauro Giavalisco, Tommy Wiklind, Tomas Dahlen

Mauro Giavalisco

We investigate the star formation histories (SFHs) of high redshift (3 . z . 5) star-forming galaxies selected based on their rest-frame ultraviolet (UV) colors in the CANDELS/GOODS-S field. By comparing the results from the spectral-energy- distribution-fitting analysis with two different assumptions about the SFHs — i.e., exponentially declining SFHs as well as increasing ones, we conclude that the SFHs of high-redshift star-forming galaxies increase with time rather than exponentially decline. We also examine the correlations between the star formation rates (SFRs) and the stellar masses. When the galaxies are fit with rising SFRs, we find that the trend seen …

Go to article

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 …

Go to article

From Voids To Coma: The Prevalence Of Pre-Processing In The Local Universe, R. A. Gutermuth Jan 2014

From Voids To Coma: The Prevalence Of Pre-Processing In The Local Universe, R. A. Gutermuth

Robert A. Gutermuth

We examine the effects of pre-processing across the Coma Supercluster, including 3505 galaxies over ∼500 deg2, by quantifying the degree to which star-forming (SF) activity is quenched as a function of environment. We characterize environment using the complementary techniques of Voronoi Tessellation, to measure the density field, and the Minimal Spanning Tree, to define continuous structures, and so we measure SF activity as a function of local density and the type of environment (cluster, group, filament, and void), and quantify the degree to which environment contributes to quenching of SF activity. Our sample covers over two orders of magnitude in …

Go to article

New Observations Of Z~7 Galaxies: Evidence For A Patch Reionization, L. Pentericci, E. Vanzella, A. Fontana, M. Castellano, T. Treu, A. Mesinger, M. Dijkstra, A. Grazian, B. Bradac, S. Cristiani, A. Galametz, Mauro Giavalisco, E. Giallongo, R. Maiolino, D. Paris, P. Santini Jan 2014

New Observations Of Z~7 Galaxies: Evidence For A Patch Reionization, L. Pentericci, E. Vanzella, A. Fontana, M. Castellano, T. Treu, A. Mesinger, M. Dijkstra, A. Grazian, B. Bradac, S. Cristiani, A. Galametz, Mauro Giavalisco, E. Giallongo, R. Maiolino, D. Paris, P. Santini

Mauro Giavalisco

We present new results from our search for z∼ 7 galaxies from deep spectroscopic observations of candidate z-dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only 2 galaxies have robust redshift identifications, one from its Lyα emission line at z=6.65, the other from its Lyman-break, i.e. the continuum discontinuity at the Lyα wavelength consistent with a redshift 6.42, but with no emission line. In addition, for 23 galaxies we present deep limits in the Lyα EW derived from the non detections in ultra-deep observations. Using this new data as well as previous …

Go to article

Creation Of Peanut-Shaped Bulges Via The Slow Mode Of Bar Growth, Michael S. Peterson, Martin D. Weinberg, Neal S. Katz Jan 2014

Creation Of Peanut-Shaped Bulges Via The Slow Mode Of Bar Growth, Michael S. Peterson, Martin D. Weinberg, Neal S. Katz

Neal S. Katz

Recent theoretical work has implicated fast bar formation modes and subsequent evolution as the creation mechanism for the observed peanut-shaped bulges in some edge-on disk galaxies. We demonstrate an N-body simulation of a disk undergoing a contrasting slow mode of bar growth, unsubjected to a buckling instability, which nonetheless grows the 4:1 orbit family responsible for a peanut-shaped bulge. We also present a simulation with fast mode bar growth, which exhibits thickening similar to other work. A novel orbit classification method that finds dynamically distinct families is presented, allowing for a detailed analysis of angular momentum transfer channels within the …

Go to article

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 Jan 2014

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 …

Go to article

The Evolution Of Clustering Length, Large Scale Bias, And Host Halo Mass At 2, A. Durkalec, O. Le Fevre, A. Pollo, S. De La Torre, P. Cassata, B. Garilli, V. Le Brun, B.C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Fonatana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, S. Paltani, B. Ribero, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, L. Tresse, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, 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 Evolution Of Clustering Length, Large Scale Bias, And Host Halo Mass At 2, A. Durkalec, O. Le Fevre, A. Pollo, S. De La Torre, P. Cassata, B. Garilli, V. Le Brun, B.C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Fonatana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, S. Paltani, B. Ribero, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, L. Tresse, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, J. Dunlop, S. Fotopoulou, A. Koekemoer, C. Lopez-Sanjuan, Y. Mellier, J. Pforr, M. Salvato, N. Scoville, Y. Taniguchi, P.W. Wang

Mauro Giavalisco

No abstract provided.

Go to article

An Anomalous Extinction Law In The Cep Ob3b Young Cluster: Evidence For Dust Processing During Gas Dispersal, Thomas S. Allen, Jakub J. Prchlik, Thomas S. Mageath, R. A. Gutermuth, Judith L. Pipher, Tim Naylor, R.D. Jeffries Jan 2014

An Anomalous Extinction Law In The Cep Ob3b Young Cluster: Evidence For Dust Processing During Gas Dispersal, Thomas S. Allen, Jakub J. Prchlik, Thomas S. Mageath, R. A. Gutermuth, Judith L. Pipher, Tim Naylor, R.D. Jeffries

Robert A. Gutermuth

We determine the extinction law through Cep OB3b, a young cluster of 3000 stars undergoing gas dispersal. The extinction is measured toward 76 background K giants identified with MMT/Hectospec spectra. Color excess ratios were determined toward each of the giants using V and R photometry from the literature, g, r, i, and z photometry from the Sloan Digital Sky Survey and J, H, and Ks photometry from the Two Micron All Sky Survey. These color excess ratios were then used to construct the extinction law through the dusty material associated with Cep OB3b. The extinction law through Cep OB3b is …

Go to article

The Evolving Sfr - M Relation And Ssfr Since Z≃5 From The Vuds Spectroscope Survey, L.A. M. Tasca, O. Le Fevre, N.P Hathi, D Schaerer, O Ilbert, G. Zamorani, B.C. Lemaux, P. Cassata, B Garilli, V. Le Brun, D. Maccagni, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, S. Paltani, B. Ribeiro, M. Scodeggio, V. Sommariva, M. Tali, L. Tresse, 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. Wong Jan 2014

The Evolving Sfr - M Relation And Ssfr Since Z≃5 From The Vuds Spectroscope Survey, L.A. M. Tasca, O. Le Fevre, N.P Hathi, D Schaerer, O Ilbert, G. Zamorani, B.C. Lemaux, P. Cassata, B Garilli, V. Le Brun, D. Maccagni, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, S. Paltani, B. Ribeiro, M. Scodeggio, V. Sommariva, M. Tali, L. Tresse, 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. Wong

Mauro Giavalisco

No abstract provided.

Go to article

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

Go to article

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 Jan 2014

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, …

Go to article

Budget And Accounting Of Metals At Z~0: Results From The Cos-Halos Survey, Molly S. Peeples, Jessica K. Werk, Jason Tumlinson, Benjamin D. Oppenheimer, J. Xavier Prochaska, Neal S. Katz, David H. Weinberg Jan 2014

Budget And Accounting Of Metals At Z~0: Results From The Cos-Halos Survey, Molly S. Peeples, Jessica K. Werk, Jason Tumlinson, Benjamin D. Oppenheimer, J. Xavier Prochaska, Neal S. Katz, David H. Weinberg

Neal S. Katz

We present a budget and accounting of metals in and around star-forming galaxies at z ~ 0. We combine empirically derived star formation histories with updated supernova and asymptotic giant branch yields and rates to estimate the total mass of metals produced by galaxies with present-day stellar mass of 109.3-1011.6 M☉. On the accounting side of the ledger, we show that a surprisingly constant 20%-25% mass fraction of produced metals remain in galaxies' stars, interstellar gas and interstellar dust, with little dependence of this fraction on the galaxy stellar mass (omitting those metals immediately locked up in remnants). Thus, the …

Go to article

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 …

Go to article

The Stellar Mass--Halo Mass Relation From Galaxy Clustering In Vuds: A High Star Formation Efficiency At Z≃3, A. Durkalec, O. Le Fevre, S. De La Torre, A. Pollo, P. Cassata, B. Garilli, V. Le Brun, B.C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, 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, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, 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 Stellar Mass--Halo Mass Relation From Galaxy Clustering In Vuds: A High Star Formation Efficiency At Z≃3, A. Durkalec, O. Le Fevre, S. De La Torre, A. Pollo, P. Cassata, B. Garilli, V. Le Brun, B.C. Lemaux, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, G. Zamorani, E. Zucca, R. Amorin, S. Bardelli, L.P. Cassara, M. Castellano, A. Cimatti, O. Cucciati, 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, D. Vergani, P. Capak, S. Charlot, T. Contini, J.G. Cuby, 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 relation between the galaxy stellar mass M⋆ and the dark matter halo mass Mh gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present measurements of the ratio of stellar mass to halo mass (SMHR) at redshifts 2 < z < 5, obtained from the VIMOS Ultra Deep Survey. We use halo occupation distribution (HOD) modelling of clustering measurements on ~3000 galaxies with spectroscopic redshifts to derive the dark matter halo mass Mh, and spectral energy density fitting over a large set of multi-wavelength data to derive the stellar mass M⋆ and compute the SMHR = M⋆/Mh. We find that the SMHR ranges from 1% to 2.5% for galaxies with M⋆ = 1.3 × 109 M⊙ to M⋆ = 7.4 × 109 M⊙ in DM halos with Mh = 1.3 × 1011 M⊙ to Mh = 3 × 1011 M⊙. We derive the integrated star formation efficiency (ISFE) of these galaxies and find that the star formation efficiency is a moderate 6−9% for lower mass galaxies, while it is relatively high at 16% for galaxies with the median stellar mass of the sample ~ 7 × 109 M⊙. The lower ISFE at lower masses may indicate that some efficient means of suppressing star formation is at work (like SNe feedback), while the high ISFE for the average galaxy at z ~ 3 indicates that these galaxies efficiently build up their stellar mass at a key epoch in the mass assembly process. Based on our results, we propose a possible scenario in which the average massive galaxy at z ~ 3 begins to experience truncation of its star formation within a few million years.

Go to article

The Extraordinary Far-Infrared Variation Of A Protostar: Herschel/Pacs Observations Of Lrll54361, Zoltan Balog, James Muzerolle, Kevin Flaherty, Ors H. Detre, Jeroen Bouwmann, Elise Furlan, R. A. Gutermuth, Attila Juhasz, John Bally Jan 2014

The Extraordinary Far-Infrared Variation Of A Protostar: Herschel/Pacs Observations Of Lrll54361, Zoltan Balog, James Muzerolle, Kevin Flaherty, Ors H. Detre, Jeroen Bouwmann, Elise Furlan, R. A. Gutermuth, Attila Juhasz, John Bally

Robert A. Gutermuth

We report Herschel/Photodetector Array Camera and Spectrometer (PACS) photometric observations at 70 μm and 160 μm of LRLL54361—a suspected binary protostar that exhibits periodic (P = 25.34 days) flux variations at shorter wavelengths (3.6 μm and 4.5 μm) thought to be due to pulsed accretion caused by binary motion. The PACS observations show unprecedented flux variation at these far-infrared wavelengths that are well correlated with the variations at shorter wavelengths. At 70 μm the object increases its flux by a factor of six while at 160 μm the change is about a factor of two, consistent with the wavelength dependence …

Go to article

Star Cluster Formation And Feedback, Mark R. Krumholz, Matthew R. Bate, Hector. G. Arce, James E. Dale, R. A. Gutermuth, Richard I. Klein, Zhi-Yun Li, Fumitaka Nakamura, Qizhou Zhang Jan 2014

Star Cluster Formation And Feedback, Mark R. Krumholz, Matthew R. Bate, Hector. G. Arce, James E. Dale, R. A. Gutermuth, Richard I. Klein, Zhi-Yun Li, Fumitaka Nakamura, Qizhou Zhang

Robert A. Gutermuth

No abstract provided.

Go to article

Csi 2264: Simultaneous Optical And Infrared Light Curves Of Young Disk-Bearing Stars In Ngc 2264 With Corot And Spitzer--Evidence For Multiple Origins Of Variability, Ann Marie Cody, John Stauffer, Annie Baglin, Giuseppina Micela, Luisa M. Rebull, Ettore Flaccomio, Maria Morales-Calderon, Suzanne Aigrain, Jerome Bouvier, Lynne A. Hillenbrand, R. A. Gutermuth, Inseok Song, Neal Turner, Silvia H.P. Alencar, Konstanze Zwintz, Peter Plavchan, John Carpenter, Krzysztof Findeisen, Sean Carey, Susan Terebey, Lee Hartman, Nuria Calvet, Paula Teixeira, Frederick J. Vrba, Scott Wolk, Kevin Covey, Katja Poppenhaeger, Hanz Moritz Gunther, Jan Forbrich, Barbara Whitney, Laura Affer, William Herbst, Joseph Hora, David Borrado, Jon Hotzman, Franck Marchis, Kenneth Wood, Marcelo Medeiros Guimares, Jorge Lillo Box, Ed Gillen, Amy Mcquillan, Catherine Espaillat, Lori Allen, Paola D'Alessio, Fabio Fatava Jan 2014

Csi 2264: Simultaneous Optical And Infrared Light Curves Of Young Disk-Bearing Stars In Ngc 2264 With Corot And Spitzer--Evidence For Multiple Origins Of Variability, Ann Marie Cody, John Stauffer, Annie Baglin, Giuseppina Micela, Luisa M. Rebull, Ettore Flaccomio, Maria Morales-Calderon, Suzanne Aigrain, Jerome Bouvier, Lynne A. Hillenbrand, R. A. Gutermuth, Inseok Song, Neal Turner, Silvia H.P. Alencar, Konstanze Zwintz, Peter Plavchan, John Carpenter, Krzysztof Findeisen, Sean Carey, Susan Terebey, Lee Hartman, Nuria Calvet, Paula Teixeira, Frederick J. Vrba, Scott Wolk, Kevin Covey, Katja Poppenhaeger, Hanz Moritz Gunther, Jan Forbrich, Barbara Whitney, Laura Affer, William Herbst, Joseph Hora, David Borrado, Jon Hotzman, Franck Marchis, Kenneth Wood, Marcelo Medeiros Guimares, Jorge Lillo Box, Ed Gillen, Amy Mcquillan, Catherine Espaillat, Lori Allen, Paola D'Alessio, Fabio Fatava

Robert A. Gutermuth

We present the Coordinated Synoptic Investigation of NGC 2264, a continuous 30 day multi-wavelength photometric monitoring campaign on more than 1000 young cluster members using 16 telescopes. The unprecedented combination of multi-wavelength, high-precision, high-cadence, and long-duration data opens a new window into the time domain behavior of young stellar objects. Here we provide an overview of the observations, focusing on results from Spitzer and CoRoT. The highlight of this work is detailed analysis of 162 classical T Tauri stars for which we can probe optical and mid-infrared flux variations to 1% amplitudes and sub-hour timescales. We present a morphological variability …

Go to article

Discovery Of A Rich Proto-Cluster At Z=2.9 And Associated Diffuse Cold Gas In The Vimos Ultra-Deep Survey (Vuds), O. Cucciati, G. Zamoriani, B.C. Lemaux, S. Bardelli, A. Cimatti, O. Le Fevre, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, P. Capak, L. Cassara, M. Castellano, 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. Taniguichi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville Jan 2014

Discovery Of A Rich Proto-Cluster At Z=2.9 And Associated Diffuse Cold Gas In The Vimos Ultra-Deep Survey (Vuds), O. Cucciati, G. Zamoriani, B.C. Lemaux, S. Bardelli, A. Cimatti, O. Le Fevre, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, L.A.M. Tasca, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, P. Capak, L. Cassara, M. Castellano, 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. Taniguichi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, C. Lopez-Sanjuan, Y. Mellier, N. Scoville

Mauro Giavalisco

No abstract provided.

Go to article

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 …

Go to article

Next Last