Jong-Hak Woo

Cosmic Evolution of Black Holes and Spheroids. IV. The BH Mass - Spheroid Luminosity Relation (2009)

Bennert, Vardha Nicola, Treu, Tommaso, Woo, Jong-Hak, Malkan, Matthew A., Bris, Alexandre Le, Auger, Matthew W., ...

From high-resolution images of 23 Seyfert-1 galaxies at z=0.36 and z=0.57 obtained with the Near Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST), we determine...

The Lick AGN Monitoring Project: Photometric Light Curves and Optical Variability Characteristics (2009)

Walsh, Jonelle L., Minezaki, Takeo, Bentz, Misty C., Barth, Aaron J., Baliber, Nairn, Li, Weidong, ...

The Lick AGN Monitoring Project targeted 13 nearby Seyfert 1 galaxies with the intent of measuring the masses of their central black holes using reverberation mapping. The sample includes 12 galaxies...

The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta (2009)

Bentz, Misty C., Walsh, Jonelle L., Barth, Aaron J., Baliber, Nairn, Bennert, Nicola, Canalizo, Gabriela, ...

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05)...

Exploring the disk-jet connection from the properties of narrow line regions in powerful young radio-loud AGNs (2008)

Kawakatu, Nozomu, Nagao, Tohru, Woo, Jong-Hak

We investigate the optical emission-line flux ratios of narrow-line regions, in order to determine whether the formation of AGN jets requires specific accretion conditions. We find that bright...

First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151 (2008)

Bentz, Misty C., Walsh, Jonelle L., Barth, Aaron J., Baliber, Nairn, Bennert, Nicola, Canalizo, Gabriela, ...

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 13 nearby (z < 0.05)...

MgII Line Variability of High Luminosity Quasars (2008)

Woo, Jong-Hak

We monitored five high-luminosity quasars with lambda L_{3000A} > 10^45 erg s^-1 at 0.4 < z < 0.6 to measure flux variability of the MgII 2798 line and explore feasibility of reverberation mapping...

Late-time observations of SN2006gy: Still Going Strong (2008)

Smith, Nathan, Foley, Ryan J., Bloom, Joshua S., Li, Weidong, Filippenko, Alexei V., Gavazzi, Raphael, ...

Owing to its extremely high luminosity and long duration, SN2006gy radiated more energy in visual light than any other known SN. Two hypotheses to explain its high luminosity -- that it was powered...

AMUSE-Virgo I. Super-massive black holes in low-mass spheroids (2007)

Gallo, Elena, Treu, Tommaso, Jacob, Jeremy, Woo, Jong-Hak, Marshall, Phil, Antonucci, Robert

We present the first results from the AGN Multiwavelength Survey of Early-type galaxies in the Virgo cluster (AMUSE-Virgo). This large program targets 100 early-type galaxies with the Advanced CCD...

Comparing and calibrating black hole mass estimators for distant active galactic nuclei (2007)

McGill, Kathryn L., Woo, Jong-Hak, Treu, Tommaso, Malkan, Matthew A.

Black hole mass is a fundamental property of active galactic nuclei (AGNs). In the distant universe, black hole mass is commonly estimated using the MgII, Hbeta, or Halpha emission line widths and...

The UV Continuum of Quasars: Models and SDSS Spectral Slopes (2007)

Davis, Shane W., Woo, Jong-Hak, Blaes, Omer M.

We measure long (2200-4000 ang) and short (1450-2200 ang) wavelength spectral slopes \alpha (F_\nu proportional to \nu^\alpha) for quasar spectra from the Sloan Digital Sky Survey. The long and short...

Cosmic Evolution of Black Holes and Spheroids. II: Scaling Relations at z=0.36 (2007)

Treu, Tommaso, Woo, Jong-Hak, Malkan, Matthew A., Blandford, Roger D.

We combine Hubble Space Telescope images of a sample of 20 Seyfert galaxies at z=0.36 with spectroscopic information from the Keck Telescope to determine the black hole mass - spheroid luminosity...

Cosmic Evolution of Black Holes and Spheroids. I: The M_BH-sigma Relation at z=0.36 (2006)

Woo, Jong-Hak, Treu, Tommaso, Malkan, Matthew A., Blandford, Roger D.

We test the evolution of the correlation between black hole mass and bulge velocity dispersion (M$_{\rm BH}-\sigma$), using a carefully selected sample of 14 Seyfert 1 galaxies at $z=0.36\pm0.01$. We...

Y2 Isochrones with an Improved Core Overshoot (2004)

Demarque, Pierre, Woo, Jong-Hak, Kim, Yong-Cheol, Yi, Sukyoung

Convective core overshoot affects stellar evolution rates and the dating of stellar populations. In this paper, we provide a patch to the $Y^2$ isochrones with an improved treatment of convective...

The Fundamental Plane Evolution of Active Galactic Nucleus Host Galaxies (2004)

Woo, Jong-Hak, Urry, Meg, Lira, Paulina, Van Der Marel, Roeland, Maza, Jose

We measured the stellar velocity dispersions of 15 active galactic nucleus (AGN) host galaxies at redshifts as high as $\sim 0.34$. Combining these with published velocity dispersion measurements...

The Independence of AGN Black Hole Mass and Radio-Loudness (2002)

Woo, Jong-Hak, Urry, C. Megan

We revisit the issue of whether radio loudness in AGN is associated with central black hole mass, as has been suggested in the literature. We present new estimates of black hole mass for 295 AGN...

AGN Black Hole Masses and Bolometric Luminosities (2002)

Woo, Jong-Hak, Urry, C. Megan

Black hole mass, along with mass accretion rate, is a fundamental property of active galactic nuclei. Black hole mass sets an approximate upper limit to AGN energetics via the Eddington limit. We...

Empirical Constraints on Convective Core Overshoot (2001)

Woo, Jong-Hak, Demarque, Pierre

In stellar evolution calculations, the local pressure scale height is often used to empirically constrain the amount of convective core overshoot. However, this method brings unsatisfactory results...

Horizontal-Branch Stars as an Age Indicator (1999)

Lee, Young-Wook, Yoon, Suk-Jin, Lee, Hyun-chul, Woo, Jong-Hak

Surface temperature distribution of horizontal-branch (HB) stars is very sensitive to age in old stellar systems, which makes it an attractive age indicator. In this paper, we present the recent...