A5082662819- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Nuclear Physics and Applications
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- Advanced X-ray and CT Imaging
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- SAS software applications and methods
- Crystal Structures and Properties
- Neutrino Physics Research
- Relativity and Gravitational Theory
Center for Astrophysics Harvard & Smithsonian
2014-2023
Constituency for Africa
2021
Smithsonian Institution
2004-2020
Smithsonian Astrophysical Observatory
2005-2015
Harvard University Press
2000-2015
Harvard University
1998-2012
Mount Washington Observatory
2009
Universidad Nacional Autónoma de México
2009
Azienda Ospedaliera Sant'Andrea
2008
Community Farm Alliance
1999-2005
A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of exciting science opportunities next decade. The Large Synoptic Survey Telescope (LSST) have an effective aperture 6.7 meters and imaging camera field view 9.6 deg^2, be devoted ten-year 20,000 deg^2 south +15 deg. Each pointing imaged 2000 times fifteen second exposures six broad from 0.35 1.1 microns, total point-source depth r~27.5. LSST Science Book describes basic...
We present 1210 Johnson/Cousins B, V, R, and I photometric observations of 22 recent Type Ia supernovae (SNe Ia): SNe 1993ac, 1993ae, 1994M, 1994S, 1994T, 1994Q, 1994ae, 1995D, 1995E, 1995al, 1995ac, 1995ak, 1995bd, 1996C, 1996X, 1996Z, 1996ab, 1996ai, 1996bk, 1996bl, 1996bo, 1996bv. Most the photometry was obtained at Fred Lawrence Whipple Observatory Harvard-Smithsonian Center for Astrophysics in a cooperative observing plan aimed improving database Ia. The redshifts sample range from cz =...
We present the results of 2MASS Redshift Survey (2MRS), a ten-year project to map full three-dimensional distribution galaxies in nearby universe. The Two Micron All Sky (2MASS) was completed 2003 and its final data products, including an extended source catalog (XSC), are available online. XSC contains nearly million with Ks ⩽ 13.5 mag is essentially complete mostly unaffected by interstellar extinction stellar confusion down galactic latitude |b| = 5° for bright galaxies. Near-infrared...
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains largest number homogeneously observed reduced nearby SNe Ia (z ≲ 0.08) published to date. It more than doubles sample, bringing SN cosmology point where systematic uncertainties dominate. Our natural system has a precision ≲0.02 mag in BVRIr'i' ≲0.04...
We measured the K-band luminosity function using a complete sample of 4192 morphologically typed 2MASS galaxies with μ = 20 mag arcsec-2 isophotal magnitudes 7 < K20 11.25 spread over 2.12 sr. Early-type (T ≤ -0.5) and late-type > have similarly shaped functions, αe -0.92 ± 0.10 αl -0.87 0.09. The early-type are brighter, MK*e -23.53 0.06 compared to MK*l -22.98 mag, but less numerous, n*e (0.45 0.06) × 10-2 h3 Mpc-3 n*l (1.01 0.13) for H0 100 h km s-1 Mpc-1, such that slightly dominate...
In the present-day universe, supermassive black hole masses (MBH) appear to be strongly correlated with their galaxy's bulge luminosity, among other properties. this study, we explore analogous relationship between MBH, derived using virial method, and stellar R-band luminosity (Lr) or mass (M*) at epochs of 1 < z 4.5 a sample 31 gravitationally lensed AGNs 20 non-lensed AGNs. At redshifts > 1.7 (10--12 Gyrs ago), find that observed MBH--Lr relation is nearly same (to within ~0.3 mag)...
view Abstract Citations (347) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On model-dependent bounds on H 0 from gravitational images : application to Q 0957+561 A, B. Falco, E. ; Gorenstein, M. V. Shapiro, I. The of a background source formed by foreground mass distribution in matter-dominated Friedmann cosmology are considered. A transformation is presented that leaves unchanged the image observables, including positions, relative...
We present UBVRI photometry of 44 Type Ia supernovae (SNe Ia) observed from 1997 to 2001 as part a continuing monitoring campaign at the Fred Lawrence Whipple Observatory Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is largest homogeneously reduced sample SNe date, nearly doubling number well-observed, nearby with published multicolor CCD light curves. large U-band unique addition, important connections high redshift. decline rate SN curves...
We present ground-based and Swift photometric spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at center PGC 043234 ($d\simeq90$ Mpc) by All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity $L\simeq10^{44}$ ergs s$^{-1}$ total integrated energy $E\simeq7\times10^{50}$ radiated over $\sim6$ months presented. UV/optical emission is well-fit blackbody with roughly constant temperature $T\sim35,000$ K, while...
We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as most luminous supernova yet found. At redshift z = 0.2326, reached an absolute magnitude M_{u,AB} -23.5+/-0.1 and bolometric luminosity L_bol (2.2+/-0.2)x 10^45 ergs s^-1, is more than twice any previously known supernova. It has several major features characteristic hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources progenitors are currently poorly understood. In contrast to SLSNe-I that reside in...
The Zwicky Catalog of galaxies (ZC), with mZw≤15.5, has been the basis for Center Astrophysics (CfA) redshift surveys. To date, analyses ZC and surveys based on it have relied heterogeneous sets galaxy coordinates redshifts. Here we correct some inadequacies previous catalogs by providing (1) ≲2 '' errors all 19,369 catalog galaxies, (2) homogeneously estimated redshifts majority (98%) data taken at CfA (14,632 spectra), (3) an estimate remaining "blunder" rate both those compiled from...
The localization of the short-duration, hard-spectrum GRB 050509b was a watershed event. Thanks to nearly immediate relay position by Swift, we began imaging field 8 minutes after burst and continued for following days. No convincing optical/infrared candidate afterglow or supernova found object. We present re-analysis XRT find an absolute that is ~4" west reported previously. Close this bright elliptical galaxy with redshift z=0.2248, about 1' from center rich cluster galaxies. Based on...
We use the microlensing variability observed for 11 gravitationally lensed quasars to show that accretion disk size at a rest-frame wavelength of 2500 Å is related black hole mass by log(R2500/cm) = (15.78 ± 0.12) + (0.80 0.17)log(MBH/109 M☉). This scaling consistent with expectation from thin-disk theory (R ∝ M2/3BH), but when interpreted in terms standard model (T R−3/4), it implies holes radiate very low efficiency, log(η) −1.77 0.29 log(L/LE), where . Only making maximum reasonable...
Optical photometry is presented for the quadruple gravitational lens PG1115+080. A preliminary reduction of data taken from November 1995 to June 1996 gives component ``C'' leading ``B'' by 23.7+/-3.4 days and components ``A1'' ``A2'' 9.4 days. range models has been fit image positions, none which an adequate fit. The best fitting most physically plausible these, taking lensing galaxy associated group galaxies be singular isothermal spheres, a Hubble constant 42 km/s/Mpc Omega=1, with...
We combine photometry and lens modeling to study the properties of 17 gravitational galaxies between z = 0.1 ~1. Most are passively evolving early-type galaxies, with a few spirals. The colors, scale lengths, ellipticities similar those general population although there may be deficit apparently round produced by inclination dependence lensing cross sections. projected mass distributions aligned light ≲10°, except in presence strong external tidal perturbation, suggesting that dark matter...
We present extensive early photometric (ultraviolet through near-infrared) and spectroscopic (optical data on supernova (SN) 2008D as well X-ray analysis the associated Swift transient (XRT) 080109. Our span a time range of 5 hr before detection to 150 days after its detection, detailed allowed us derive constraints nature SN progenitor; throughout we draw comparisons with results presented in literature find several key aspects that differ. show spectrum XRT 080109 can be fit equally by an...
We report on a program to obtain Hubble Space Telescope (HST) observations of galaxy-mass gravitational lens systems at optical and infrared wavelengths. Here we discuss the properties 10 two-image (Q0142-100 = UM 673, B0218+357, SBS 0909+532, BRI 0952-0115, LBQS 1009-0252, Q1017-207 J03.13, B1030+074, HE 1104-1805, Q1208+1011, PKS 1830-211). grouped these because they have limited model constraints often show poor contrast between images galaxy. Of galaxies, seven are probably early-type...
We present rotation period measurements for 41 field M-dwarfs, all of which have masses inferred (from their parallaxes and 2MASS K-band magnitudes) to be between the hydrogen burning limit 0.35 Msol, thus should remain fully-convective throughout lifetimes. measure a wide range periods, from 0.28 days 154 days, with latter commensurate typical sensitivity our observations. Using kinematics as proxy age, we find that majority objects likely thick disk or halo members (and hence, on average,...
We present multi-band optical photometry of 94 spectroscopically confirmed Type Ia supernovae (SNe Ia) in the redshift range 0.0055–0.073, obtained between 2006 and 2011. There are a total 5522 light-curve points. show that our natural-system SN has precision ≲ 0.03 mag BVr'i', 0.06 u', 0.07 U for points brighter than 17.5 estimate it systematic uncertainty 0.014, 0.010, 0.012, 0.046, 0.073 BVr'i'u'U, respectively. Comparisons standard-system with published light curves comparison stars...
In the effort to characterize masses, radii, and atmospheres of potentially habitable exoplanets, there is an urgent need find examples such planets transiting nearby M dwarfs. The MEarth Project ongoing do so, as a ground-based photometric survey designed detect exoplanets small 2 Earth radii mid-to-late dwarfs within 33 pc Sun. Unfortunately, identifying transits in monitoring complicated both by intrinsic stellar variability that common among these stars nocturnal cadence, atmospheric...
view Abstract Citations (170) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Degeneracies in Parameter Estimates for Models of Gravitational Lens Systems Gorenstein, M. V. ; Falco, E. Shapiro, I. Observations gravitational lens systems may yield useful estimates characteristics the lenses and cosmological parameters. However, nature these observations restricts types that can be determined. We demonstrate some inherent restrictions, i.e.,...