C. J. Grier
A5019516607- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Calibration and Measurement Techniques
- Particle Accelerators and Free-Electron Lasers
- Plant Water Relations and Carbon Dynamics
- Soil Moisture and Remote Sensing
- Underwater Acoustics Research
- Spectroscopy and Laser Applications
- Relativity and Gravitational Theory
- Spectroscopy Techniques in Biomedical and Chemical Research
- Superconducting Materials and Applications
- Cosmology and Gravitation Theories
- Indoor and Outdoor Localization Technologies
- Ionosphere and magnetosphere dynamics
University of Wisconsin–Madison
2023-2024
University of Arizona
2019-2024
University of Wisconsin System
2024
The Ohio State University
2012-2021
Pennsylvania State University
2014-2021
Harvard University Press
2019
Max Planck Institute for Radio Astronomy
2013
Georgia State University
2011
European Southern Observatory
2009
Observatoire de Paris
2009
We present an updated and revised analysis of the relationship between Hβ broad-line region (BLR) radius luminosity active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions host galaxies nine new AGNs imaged with Hubble Space Telescope Wide Field Camera 3. The allow us to create "AGN-free" images galaxies, from which measure starlight contribution optical measured through ground-based spectroscopic aperture. also incorporate 20...
We present reverberation mapping results from the first year of combined spectroscopic and photometric observations Sloan Digital Sky Survey Reverberation Mapping Project. successfully recover time delays between $g+i$-band emission broad H$\beta$ line for a total 44 quasars, H$\alpha$ in 18 quasars. Time are computed using JAVELIN CREAM software traditional interpolated cross-correlation function (ICCF): Using well defined criteria, we report measurements 32 13 lags with JAVELIN, 42 17...
The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is first one for SDSS-V, fifth generation survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole (BHM), and Local Volume (LVM). This contains extensive targeting information two multi-object spectroscopy programs (MWM BHM), including input catalogs selection functions their numerous objectives. We describe production databases calibration- scientifically-focused...
Abstract We present the final data from Sloan Digital Sky Survey (SDSS) Reverberation Mapping (RM) project, a precursor to SDSS-V Black Hole Mapper RM program. This set includes 11 yr photometric and 7 spectroscopic light curves for 849 broad-line quasars over redshift range of 0.1 < z 4.5 luminosity L bol = 10 44−47.5 erg s −1 , along with spectral variability measurements. report 23, 81, 125, 110 lags (relative optical continuum variability) broad H α β Mg ii C iv using SDSS-RM sample,...
We present multi-wavelength observations that trace more than 40 years in the life of active galactic nucleus (AGN) Mrk 590, traditionally known as a classic Seyfert 1 galaxy. From spectra recently obtained from HST, Chandra, and Large Binocular Telescope, we find activity 590 has diminished so significantly continuum luminosity is factor 100 lower peak probed by our long baseline observations. Furthermore, broad emission lines, once prominent UV/optical spectrum, have all but disappeared....
We present velocity-resolved reverberation results for five active galactic nuclei. recovered velocity-delay maps using the maximum-entropy method four objects: Mrk 335, 1501, 3C120, and PG2130+099. For fifth, 6, we were only able to measure mean time delays in different velocity bins of Hbeta emission line. The show unique dynamical signatures each object. Balmer lines kinematic consistent with both an inclined disk infalling gas, but HeII 4686 line is suggestive inflow. PG 2130+099 signs...
Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and X-rays. This is densest extended AGN continuum sampling ever obtained, with a mean rate <0.5 day. Approximately daily HST UV was also obtained. The light curves show strong correlations (r_max = 0.57 - 0.90) clearest measurement to date interband lags. These lags are well-fit by \tau propto \lambda^4/3 wavelength dependence, normalization that indicates...
We present the results from a detailed analysis of photometric and spectrophotometric data on five Seyfert 1 galaxies observed as part recent reverberation mapping program. The were collected at several observatories over 140 day span beginning in 2010 August ending 2011 January. obtained high sampling-rate light curves for Mrk 335, 1501, 3C 120, 6, PG 2130+099, which we have measured time lag between variations 5100 Å continuum Hβ broad emission line. then used these measurements to...
Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on C iv, Hα, Hβ broad emission lines. Our is upon that Greene, Peng, & Ludwig, expanded new near-IR spectroscopic observations, consistently analyzed high signal-to-noise ratio (S/N) consistent continuum luminosity at 5100 Å. We find BH full width...
ABSTRACT We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multiwavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters ( BVRI and ugriz ). Combined with ultraviolet the Hubble Space Telescope Swift , we confirm significant time delays between continuum bands as a function wavelength, extending wavelength coverage 1158 Å z band (~9160 Å). find that lags at wavelengths longer...
We describe the first results from a six-month long reverberation-mapping experiment in ultraviolet based on 170 observations of Seyfert 1 galaxy NGC 5548 with Cosmic Origins Spectrograph Hubble Space Telescope. Significant correlated variability is found continuum and broad emission lines, amplitudes ranging ~30% to factor two lines three continuum. The variations all strong lag behind those continuum, He II 1640 lagging by ~2.5 days Lyman alpha 1215, C IV 1550, Si 1400 ~5-6 days....
We present a detailed characterization of the 849 broad-line quasars from Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Our quasar sample covers redshift range 0.1<z<4.5 and is flux-limited to i_PSF<21.7 without any other cuts on properties. The main includes: 1) spectral measurements continuum broad emission lines for individual objects coadded first-season spectroscopy in 2014; 2) identification narrow absorption spectra; 3) optical variability properties multi-epoch...
We present new stellar velocity dispersion measurements for four luminous quasars with the Near-Infrared Integral Field Spectrometer instrument and ALTAIR laser guide star adaptive optics system on Gemini North 8 m telescope. Stellar of supermassive black hole (BH) masses in are necessary to investigate coevolution BHs galaxies, trace details accretion, probe nature feedback. find that higher-luminosity higher-mass not offset respect MBH–σ* relation exhibited by lower-luminosity active...
We use 317,000 emission-line galaxies from the Sloan Digital Sky Survey to investigate line-ratio selection of active galactic nuclei (AGNs). In particular, we demonstrate that "star formation (SF) dilution" by H ii regions causes a significant bias against AGN in low-mass, blue, star-forming, disk-dominated galaxies. This is responsible for observed preference AGNs among high-mass, green, moderately bulge-dominated hosts. account and simulate intrinsic population using physically motivated...
Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses these distant objects, but so far there have been limited attempts and success given the practical difficulties RM this regime. Here we report preliminary results 15 BLR lag from Sloan Digital Sky Survey Mapping (SDSS-RM) project, a dedicated program with multi-object spectroscopy designed over wide redshift range. The based on 2014 spectroscopic...
Abstract We present inferences on the geometry and kinematics of broad-H β line-emitting region in four active galactic nuclei monitored as part fall 2010 reverberation mapping campaign at MDM Observatory led by Ohio State University. From modeling continuum variability response emission-line profile changes a function time, we infer H -emitting broad-line regions (BLRs) to be thick disks that are close face-on observer with well-described either elliptical orbits or inflowing gas. measure...
Quasar emission lines are often shifted from the systemic velocity due to various dynamical and radiative processes in line-emitting region. The level of these shifts depends both on line species quasar properties. We study for peaks narrow broad relative using a sample 849 quasars Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. coadded (from 32 epochs) spectra individual have sufficient signal-to-noise ratio (SNR) measure stellar absorption provide reliable estimates, as...
Abstract It is well known that reverberation mapping of active galactic nuclei (AGNs) reveals a relationship between AGN luminosity and the size broad-line region, use this relationship, combined with Doppler width broad emission line, enables an estimate mass black hole at center nucleus based on single spectrum. An unresolved key issue choice parameter used to characterize line width, either FWHM or dispersion <?CDATA ${\sigma }_{\mathrm{line}}$?> (the square root second moment profile)....
We present the first results from an optical reverberation mapping campaign executed in 2014, targeting active galactic nuclei (AGN) MCG+08-11-011, NGC 2617, 4051, 3C 382, and Mrk 374. Our targets have diverse interesting observational properties, including a "changing look" AGN broad-line radio galaxy. Based on continuum-H$\beta$ lags, we measure black hole masses for all five targets. also obtain H$\gamma$ He{\sc ii}\,$\lambda 4686$ lags objects except 382. The indicate radial...
We present reverberation-mapping lags and black-hole mass measurements using the CIV 1549 broad emission line from a sample of 349 quasars monitored as part Sloan Digital Sky Survey Reverberation Mapping Project. Our data span four years spectroscopic photometric monitoring for total baseline 1300 days. report significant time delays between continuum in 52 quasars, with an estimated false-positive detection rate 10%. analysis marginal lag indicates that there are on order 100 additional...
We present the first results from ongoing, intensive, multi-wavelength monitoring program of luminous Seyfert 1 galaxy Mrk 817. While this AGN was, in part, selected for its historically unobscured nature, we discovered that X-ray spectrum is highly absorbed, and there are new blueshifted, broad narrow UV absorption lines, which suggest a dust-free, ionized obscurer located at inner line region partially covers central source. Despite obscuration, measure optical continuum reverberation lags...
Abstract We present reverberation mapping results for the Mg ii λ 2800 Å broad emission line in a sample of 193 quasars at <?CDATA $0.35\lt z\lt 1.7$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>0.35</mml:mn> <mml:mo><</mml:mo> <mml:mi>z</mml:mi> <mml:mn>1.7</mml:mn> </mml:math> with photometric and spectroscopic monitoring observations from Sloan Digital Sky Survey Reverberation Mapping project during 2014–2017. find significant time lags between...
Repeat scans by the Sloan Digital Sky Survey (SDSS) of a 278-deg2 stripe along celestial equator have yielded an average over 10 observations each for nearly 8000 spectroscopically confirmed quasars. Over 2500 these quasars are in redshift range such that C ivλ 1549 emission line is visible SDSS spectrum. Utilizing width iv lines and luminosity nearby continuum, we estimate black hole masses objects. In effort to isolate effects mass on photometric variability our data set, create several...
The narrow [O iii] λλ4959, 5007 emission-line fluxes in the spectrum of well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that narrow-line-emitting region has a radius only 1–3 pc and is denser (ne ∼ 105 cm−3) than previously supposed. line width consistent virial motions at given previous determinations black hole mass. Since flux usually assumed be constant therefore used calibrate spectroscopic monitoring data, variability ramifications for long-term...
We study the time lags between continuum emission of quasars at different wavelengths, based on more than four years multi-band ($g$, $r$, $i$, $z$) light-curves in Pan-STARRS Medium Deep Fields. As photons from bands emerge radial ranges accretion disk, constrain sizes disks. select 240 with redshifts $z \approx 1$ or 0.3$ that are relatively line free. The light curves sampled day to month timescales, which makes it possible detect scale crossing With code JAVELIN, we typical several days...