A5034370718- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Remote Sensing in Agriculture
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Plant Water Relations and Carbon Dynamics
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Advanced Vision and Imaging
- Spectroscopy and Laser Applications
- CCD and CMOS Imaging Sensors
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Spectroscopy and Chemometric Analyses
University of California, San Diego
2016-2025
Universidad Católica Santo Domingo
2009-2023
UC San Diego Health System
2019-2023
Universidad Nacional Autónoma de México
2013
Alfred P. Sloan Foundation
2010-2013
University of California, Santa Barbara
2012
University of Arizona
2006-2009
University of California, Berkeley
2000-2006
Berkeley College
2001-2004
Center for Astrophysics Harvard & Smithsonian
1999
We analyze star formation (SF) as a function of stellar mass (M*) and redshift z in the All-Wavelength Extended Groth Strip International Survey. For 2905 field galaxies, complete to 1010(1010.8) M☉ at < 0.7(1), with Keck spectroscopic redshifts out = 1.1, we compile SF rates (SFRs) from emission lines, GALEX, Spitzer MIPS 24 μm photometry, optical-NIR M* measurements, HST morphologies. Galaxies reliable signs form distinct "main sequence" (MS), limited range SFRs given (1 σ ≲ ±0.3 dex),...
The High-z Supernova Search Team has discovered and observed 8 new supernovae in the redshift interval z=0.3-1.2. These independent observations, confirm result of Riess et al. (1998a) Perlmutter (1999) that supernova luminosity distances imply an accelerating universe. More importantly, they extend range consistently SN Ia to z~1, where signature cosmological effects opposite sign some plausible systematic effects. Consequently, these measurements not only provide another quantitative...
The DEEP2 and COMBO-17 surveys are used to study the evolution of luminosity function red blue galaxies $z \sim 1$. Schechter fits show that, since = 1$, $M^*_B$ dims by $\sim$ 1.3 mag per unit redshift for both color classes, $ϕ^*$ shows little change, while has formally nearly quadrupled. At face value, number density remained roughly constant $ z whereas that been rising. Luminosity densities support conclusions, but we note most red-galaxy occurs between our data local in highest bin,...
The DEIMOS spectrograph is a multi-object being built for Keck II. was delivered in February 2002, became operational May, and now about three-quarters of the way through its commissioning period. This paper describes major problems encountered completing spectrograph, with particular emphasis on optical quality image motion. strategies developed to deal these are described. Overall, going well, it appears that will meet all performance goals.
We describe the design and data sample from DEEP2 Galaxy Redshift Survey, densest largest precision-redshift survey of galaxies at z ~ 1 completed to date. The has conducted a comprehensive census massive galaxies, their properties, environments, large-scale structure down absolute magnitude M_B = -20 via ~90 nights observation on DEIMOS spectrograph Keck Observatory. covers an area 2.8 deg^2 divided into four separate fields, observed limiting apparent R_AB=24.1. Objects with < 0.7 are...
We characterize the mass-dependent evolution of more than 8000 galaxies using spectroscopic redshifts from DEEP2 Galaxy Redshift Survey in range 0.4 < z 1.4 and stellar masses calculated K-band photometry obtained at Palomar Observatory. This sample spans 1.5 deg2 four independent fields. Using rest-frame U - B color [O II] equivalent widths, we distinguish star-forming passive populations order to explore nature ``downsizing''—a pattern which sites active star formation shift high-mass...
Galactic winds are a prime suspect for the metal enrichment of intergalactic medium and may have strong influence on chemical evolution galaxies nature QSO absorption line systems. We use sample 1406 galaxy spectra at z~1.4 from DEEP2 redshift survey to show that blueshifted Mg II 2796, 2803 A is ubiquitous in starforming this epoch. This first detection frequent outflowing galactic z~1. The presence depth independent AGN spectral signatures or morphology; major mergers not prerequisite...
In this the first of a series Letters, we present panchromatic data set in Extended Groth Strip region sky. Our survey, All-Wavelength International Survey (AEGIS), aims to study physical properties and evolutionary processes galaxies at z ~ 1. It includes following deep, wide-field imaging sets: Chandra/ACIS X-ray, GALEX ultraviolet, CFHT/MegaCam Legacy optical, CFHT/CFH12K Hubble Space Telescope/ACS optical NICMOS near-infrared, Palomar/WIRC Spitzer/IRAC mid-infrared, Spitzer/MIPS...
We measure the evolution of stellar mass function (SMF) from z = 0–1 using multi-wavelength imaging and spectroscopic redshifts PRism MUlti-object Survey (PRIMUS) Sloan Digital Sky (SDSS). From PRIMUS we construct an i < 23 flux-limited sample ∼40, 000 galaxies at 0.2–1.0 over five fields totaling ≈5.5 deg2, SDSS select ∼170, 0.01–0.2 that analyze consistently with respect to minimize systematic errors in our evolutionary measurements. find SMF all evolves relatively little since 1, although...
We analyze star formation (SF) as a function of stellar mass (M_*) and redshift z in the All Wavelength Extended Groth Strip International Survey (AEGIS), for star-forming field galaxies with M_* >~ 10^10 M_sun out to z=1.1. The data indicate that high specific SF rates (SFR) many less massive do not represent late, irregular or recurrent, starbursts evolved galaxies. They rather seem reflect onset (initial burst) dominant episode galaxies, after which gradually declines on Gyr timescales...
In this paper we present the MOSFIRE Deep Evolution Field (MOSDEF) survey. The MOSDEF survey aims to obtain moderate-resolution (R=3000-3650) rest-frame optical spectra (~3700-7000 Angstrom) for ~1500 galaxies at 1.37<z<3.80 in three well-studied CANDELS fields: AEGIS, COSMOS, and GOODS-N. Targets are selected redshift intervals: 1.37<z<1.70, 2.09<z<2.61, 2.95<z<3.80, down fixed H_AB (F160W) magnitudes of 24.0, 24.5 25.0, respectively, using photometric spectroscopic catalogs from 3D-HST We...
The DEIMOS spectrograph has now been installed on the Keck-II telescope and commissioning is nearly complete. DEEP2 Redshift Survey, which will take approximately 120 nights at Keck Observatory over a three year period designed to utilize power of DEIMOS, began in summer 2002. multiplexing high efficiency enables us target 1000 faint galaxies per clear night. Our goal gather high-quality spectra \~60,000 with z>0.75 order study properties large scale clustering z ~ 1. survey be executed...
We model the luminosity-dependent projected two-point correlation function of DEEP2 (z ~ 1) and SDSS 0) galaxies within HOD framework. At both epochs, there is a tight between central galaxy luminosity halo mass, with slope scatter decreasing for larger masses, fraction satellite decreases at higher luminosity. find little evolution in relation mass scales host halos above same threshold. Combining these results theoretical predictions typical growth halos, we establish an evolutionary...
The evolution of the B-band galaxy luminosity function is measured using a sample more than 11,000 galaxies with spectroscopic redshifts from DEEP2 Redshift Survey. rest-frame M_B versus U-B color-magnitude diagram shows that bi-modality seen in locally still present at z > 1. Dividing trough this color bimodality into predominantly red and blue galaxies, we find each type evolves differently. Blue counts tend to shift brighter magnitudes constant number density, while remain largely...
We present results on the dust attenuation curve of z ∼ 2 galaxies using early observations from MOSFIRE Deep Evolution Field survey. Our sample consists 224 star-forming with zspec = 1.36–2.59 and high signal-to-noise ratio measurements Hα Hβ obtained Keck/MOSFIRE. construct composite spectral energy distributions (SEDs) in bins Balmer decrement to measure curve. find a that is similar SMC extinction at λ ≳ 2500 Å. At shorter wavelengths, shape identical Calzetti et al. relation, but lower...
We present Keck/LRIS spectra of over 200 galaxies with well-determined redshifts between 0.4 and 1.4. combine new measurements near-ultraviolet, low-ionization absorption lines previously measured masses, luminosities, colors, star formation rates to describe the demographics properties galactic flows. Among star-forming blue we find a net blueshift Fe ii greater than km s−1 (100 s−1) toward 2.5% (20%) galaxies. The fraction blueshifted does not vary significantly stellar mass, color, or...
We present new measurements of the evolution X-ray luminosity functions (XLFs) unabsorbed and absorbed active galactic nuclei (AGNs) out to z ∼ 5. construct samples containing 2957 sources detected at hard (2–7 keV) energies 4351 soft (0.5–2 from a compilation Chandra surveys supplemented by wide-area ASCA ROSAT. consider separately find that XLF based on either (initially neglecting absorption effects) is best described flexible model parametrization where break luminosity, normalization,...
We present the quantitative rest-frame B morphological evolution and galaxy merger fractions at 0.2 < z 1.2 as observed by All-wavelength Extended Groth Strip International Survey (AEGIS). use Gini coefficent M_20 to identify major mergers classify morphology for a volume-limited sample of 3009 galaxies brighter than 0.4 L_B^*, assuming pure luminosity 1.3 M_B per unit redshift. find that fraction remains roughly constant 10 +/- 2% 1.2. The E/S0/Sa increases from 21+/- 3% ~ 1.1 44 9% 0.3,...
In this first paper in a series we present 1298 low-redshift (z\leq0.2) optical spectra of 582 Type Ia supernovae (SNe Ia) observed from 1989 through 2008 as part the Berkeley SN Program (BSNIP). 584 199 SNe have well-calibrated light curves with measured distance moduli, and many been corrected for host-galaxy contamination. Most data were obtained using Kast double spectrograph mounted on Shane 3 m telescope at Lick Observatory typical wavelength range 3300-10,400 Ang., roughly twice wide...
Using observations from the MOSFIRE Deep Evolution Field (MOSDEF) survey, we investigate physical conditions of star-forming regions in $z\sim2.3$ galaxies, specifically electron density and ionization state. From measurements [O II]$\lambda\lambda$3726,3729 [S II]$\lambda\lambda$6716,6731 doublets, find a median $\sim250$ cm$^{-3}$ at $z\sim2.3$, an increase order magnitude compared to galaxies $z\sim0$. While are offset towards significantly higher O$_{32}$ values relative local fixed...
We present new observational determinations of the evolution 2-10keV X-ray luminosity function (XLF) AGN. utilise data from a number surveys including both 2Ms Chandra Deep Fields and AEGIS-X 200ks survey, enabling accurate measurements faint end XLF. combine direct, hard selection spectroscopic follow-up or photometric redshift estimates at z<1.2 with rest-frame UV colour pre-selection approach higher redshifts to avoid biases associated catastrophic failure redshifts. Only robust optical...
We present results on the excitation properties of z ∼ 2.3 galaxies using early observations from MOSFIRE Deep Evolution Field (MOSDEF) Survey. With its coverage full suite strong rest-frame optical emission lines, MOSDEF provides an unprecedented view spectra a representative sample distant star-forming galaxies. investigate locations in multiple emission-line diagnostic diagrams. These include [O iii]λ5007/Hβ vs. [N ii]/Hα and [S ii]λλ6717, 6731/Hα "BPT" diagrams, as well O32 R23 diagram....
We present detections of [OIII]$\lambda$4363 and direct-method metallicities for star-forming galaxies at $z=1.7-3.6$. combine new measurements from the MOSFIRE Deep Evolution Field (MOSDEF) survey with literature sources to construct a sample 18 $z>1$, spanning $7.5<1$2+log(O/H$)<8.2$ log(M$_*$/M$_{\odot})=7-10$. find that strong-line calibrations based on local analogs high-redshift reliably reproduce metallicity $z>1$ average. first mass-metallicity relation purely O/H, finding slope is...
We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em derive its distance through expanding photosphere method (EPM). SN is shown to be a Type II‐plateau (II‐P) event, with plateau lasting until about 100 explosion. identify dominant ions responsible for most absorption features seen in portion spectrum during phase. Using weakest unblended estimate photospheric velocity, we find D = 8.2 ± 0.6 Mpc, an explosion date HJD...
We report the results of an extensive imaging and spectroscopic survey in Great Observatories Origins Deep Survey (GOODS)-North field completed using DEIMOS on Keck II telescope. Observations 2018 targets a magnitude-limited sample 2911 objects to RAB = 24.4 yield secure redshifts for 1440 galaxies active galactic nuclei (AGNs) plus 96 stars. In addition associated quality assessments, our catalog also includes photometric astrometric measurements all detected R-band GOODS-North region....