A5076108889- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
- Plant and animal studies
- Astro and Planetary Science
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- CCD and CMOS Imaging Sensors
- Impact of Light on Environment and Health
- Mathematical and Theoretical Epidemiology and Ecology Models
- Pulsars and Gravitational Waves Research
- Evolutionary Game Theory and Cooperation
- Evolution and Genetic Dynamics
- Philosophy and History of Science
University of Arizona
2014-2023
Community Science and Data Center
2023
NSF’s NOIRLab
2023
National Research Council Canada
2022
Leiden University
2017
University of Minnesota, Duluth
1982-2016
Kitt Peak National Observatory
2000-2014
Association of Universities For Research In Astronomy
1996-2014
U.S. National Science Foundation
1996-2014
Las Cumbres Observatory Global Telescope Network
2006-2013
We construct dynamical models for a sample of 36 nearby galaxies with Hubble Space Telescope (HST) photometry and ground-based kinematics. The assume that each galaxy is axisymmetric, two-integral distribution function, arbitrary inclination angle, position-independent stellar mass-to-light ratio Υ, central massive dark object (MDO) mass M•. They provide acceptable fits to 32 the some value M• Υ; four cannot be fitted have kinematically decoupled cores. ratios inferred well-fitted are...
We describe a correlation between the mass M_BH of galaxy's central black hole and luminosity-weighted line-of-sight velocity dispersion sigma_e within half-light radius. The result is based on sample 26 galaxies, including 13 galaxies with new determinations masses from Hubble Space Telescope measurements stellar kinematics. best-fit = 1.2 (+-0.2) x 10^8 M_sun (sigma_e/200 km/s)^(3.75 (+-0.3))over almost three orders magnitude in M_BH; scatter at fixed only 0.30 dex most this due to...
Observations of nearby galaxies reveal a strong correlation between the mass central dark object M and velocity dispersion sigma host galaxy, form log(M/M_sun) = + b*log(sigma/sigma_0); however, published estimates slope b span wide range (3.75 to 5.3). Merritt & Ferrarese have argued that low slopes (<4) arise because neglect random measurement errors in dispersions an incorrect choice for Milky Way Galaxy. We show these explanations account at most small part range. Instead, arises...
view Abstract Citations (1626) References (136) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Atlas of Quasar Energy Distributions Elvis, Martin ; Wilkes, Belinda J. McDowell, Jonathan C. Green, Richard F. Bechtold, Jill Willner, S. P. Oey, M. Polomski, Elisha Cutri, Roc We present an atlas the spectral energy distributions (SEDs) normal, nonblazar, quasars over whole available range (radio to 10 keV X-rays) electromagnetic spectrum. The primary (UVSX)...
view Abstract Citations (1424) References (46) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Emission-Line Properties of Low-Redshift Quasi-stellar Objects Boroson, Todd A. ; Green, Richard F. Spectra covering the region λλ4300-5700 have been obtained all 87 QSOs in BQS catalog having redshifts less than 0.5. An empirical technique which allows measurement and subtraction many Fe II lines this has developed applied to these spectra. Measurements...
We derive improved versions of the relations between supermassive black hole mass (M_BH) and host-galaxy bulge velocity dispersion (sigma) luminosity (L) (the M-sigma M-L relations), based on 49 M_BH measurements 19 upper limits. Particular attention is paid to recovery intrinsic scatter (epsilon_0) in both relations. find log(M_BH / M_sun) = alpha + beta * log(sigma 200 km/s) with (alpha, beta, epsilon_0) (8.12 +/- 0.08, 4.24 0.41, 0.44 0.06) for all galaxies (8.23 3.96 0.42, 0.31...
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 investigate the extent to which Palomar-Green (PG) Bright Quasar Survey (BQS) is complete and representative of general quasar population by comparing it with imaging spectroscopy from Sloan Digital Sky (SDSS). A comparison SDSS PG photometry both stars quasars reveals need apply a color magnitude recalibration data. Using photometric catalog, we define PG's parent sample objects that are not main-sequence simulate selection this using criteria errors. This simulation shows effective U -...
Distant quasars are unique tracers to study the formation of earliest supermassive black holes (SMBHs) and history cosmic reionization. Despite extensive efforts, only two have been found at $z\ge7.5$, due a combination their low spatial density high contamination rate in quasar selection. We report discovery luminous $z=7.642$, J0313$-$1806, most distant yet known. This has bolometric luminosity $3.6\times10^{13} L_\odot$. Deep spectroscopic observations reveal SMBH with mass $(1.6\pm0.4)...
Black hole masses predicted from the Mbh-sigma relationship conflict with those Mbh-L for most luminous galaxies, such as brightest cluster galaxies (BCGs). This is because stellar velocity dispersion, sigma, increases only weakly L BCGs and other giant ellipticals. The predicts that may have Mbh approaching 10^{10}M_sol, while M-sigma always Mbh<3X10^9M_sol. We argue a plausible or even preferred description of similar luminosity. If cores in central density are formed by binary BHs, then...
Abstract We report the results of near-infrared spectroscopic observations 37 quasars in redshift range 6.3 < z ≤ 7.64, including 32 at > 6.5, forming largest quasar spectral sample this redshift. The spectra, taken with Keck, Gemini, VLT, and Magellan, allow investigations central black hole mass rest-frame ultraviolet properties. masses derived from Mg ii emission lines are (0.3–3.6) × 10 9 M ⊙ , which requires massive seed holes ≳10 3 –10 4 assuming Eddington accretion since = 30....
Black hole (BH) masses that have been measured by reverberation mapping in active galaxies fall significantly below the correlation between bulge luminosity and BH mass determined from spatially resolved kinematics of nearby normal galaxies. This discrepancy has created concern one or both techniques suffer systematic errors. We show are consistent with recently discovered relationship galaxy velocity dispersion. Therefore, luminosities probable source disagreement, not problems either...
We analyze HST+WFPC2 images of 77 early-type galaxies. Brightness profiles are classed into "core" or "power-law" forms. Cores typically rounder than power-law Nearly all power-laws with central ellipticity >=0.3 have stellar disks, implying that disks present in epsilon <0.3, but not visible due to unfavorable geometry. A few low-luminosity core galaxies also disks; these may be transition forms from power-laws. and both twisting isophotes at small radii. Core somewhat weaker color...
We present axisymmetric, orbit superposition models for 12 galaxies using data taken with the Hubble Space Telescope (HST) and ground-based observatories. In each galaxy, we detect a central black hole (BH) measure its mass to accuracies ranging from 10% 70%. demonstrate that in most cases BH detection requires both HST data. Using alone does provide an unbiased of (provided they are fitted fully general models), but at greatly reduced significance. The significant correlation host galaxy...
Bayesian decision theory can be used to model animal behaviour. In this paper we give an overview of the theoretical concepts in such models. We also review biological contexts which models have been applied, and outline some directions where future studies would useful. theory, when applied behaviour, is based on assumption that individual has sort “prior opinion” possible states world. This may, for example, a previously experienced distribution qualities food patches, or potential mates....
We present Hubble Space Telescope (HST) spectroscopy of the nucleus M31 obtained with Imaging Spectrograph (STIS). Spectra that include Ca II infrared triplet (λ ≃ 8500 Å) see only red giant stars in double brightness peaks P1 and P2. In contrast, spectra taken at λ 3600-5100 Å are sensitive to tiny blue embedded P2, lower surface galaxy. P2 has a K-type spectrum, but we find an A-type spectrum: it shows strong Balmer absorption lines. Hence, is not because AGN light rather dominated by hot...
If an animal forages for prey that are distributed in patches, it must use some rule to decide when leave one patch and go on another. Charnov's marginal value theorem tells should a patch, but does not tell how patch. This is important if patches vary quality the forager its experience best In this paper mathematically tractable stochastic model presented which animals forage systematically three possible strategies (stopping rules) considered. The found compared with giving-up time (GUT)...
Galaxies that contain bulges appear to central black holes whose masses correlate with the velocity dispersion of bulge. We show no corresponding relationship applies in pure disk galaxy M33. Three-integral dynamical models fit Hubble Space Telescope WFPC2 photometry and Imaging Spectrograph spectroscopy best if hole mass is zero. The upper limit 1500 M⊙. This significantly below expected from nucleus far any predicted kinematics. Our results suggest supermassive are associated only not their disks.
We combine the results from several HST investigations of central structure early-type galaxies to generate a large sample parameterized surface photometry. The studies included were those that used "Nuker law" characterize inner light distributions galaxies. comprises WFPC1 and WFPC2 V band observations published earlier by our group, R photometry Rest et al., NICMOS H Ravindranath al. Quillen BCG I Laine distribution logarithmic slopes profiles strongly affirms elliptical with Mv < -19 is...
We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating work Elvis et al. (1994) by using high-quality data obtained with several space and ground-based telescopes, including NASA's Great Observatories. present an atlas SEDs 85 optically bright, non-blazar quasars over electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet 58 radio-loud quasars. Most objects quasi-simultaneous ultraviolet-optical...