Microlensing Evidence That A Type 1 Quasar Is Viewed Face On (2009)
Poindexter, Shawn, Kochanek, Christopher S.
Using a microlensing analysis of 11-years of OGLE V-band photometry of the four image gravitational lens Q2237+0305, we measure the inclination i of the accretion disk to be cos i > 0.63 at 68%...
The Transverse Peculiar Velocity of the Q2237+0305 Lens Galaxy and the Mean Mass of Its Stars (2009)
Poindexter, Shawn, Kochanek, Christopher S.
Using 11-years of OGLE V-band photometry of Q2237+0305, we measure the transverse velocity of the lens galaxy and the mean mass of its stars. We can do so because, for the first time, we fully...
Kozlowski, Szymon, Kochanek, Christopher S., Udalski, A., Wyrzykowski, L., Soszynski, I., Szymanski, M. K., ...
Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular...
Kate Brand, Arjun Dey, Buell T. Jannuzi, Christopher S. Kochanek, Almus T. Kenter, ...
The XBoötes Survey is a 5-ks Chandra survey of the Boötes Field of the NOAO Deep Wide-Field Survey (NDWFS). This survey is unique in that it is the largest (9.3 deg2), contiguous region imaged in...
Prieto, Jose L., Sellgren, Kris, Thompson, Todd A., Kochanek, Christopher S.
We present a Spitzer/IRS low-resolution mid-infrared spectrum (5-14 micron) of the luminous transient discovered in the nearby galaxy NGC 300 in May 2008. The spectrum, obtained three months after...
Hickox, Ryan C., Jones, Christine, Forman, William R., Murray, Stephen S., Kochanek, Christopher S., Eisenstein, Daniel, ...
We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of...
Discovery of 5000 Active Galactic Nuclei behind the Magellanic Clouds (2009)
Kozlowski, Szymon, Kochanek, Christopher S.
We show that using mid-IR color selection to find active galactic nuclei (AGN) is as effective in dense stellar fields such as the Magellanic Clouds as it is in extragalactic fields with low stellar...
MacLeod, Chelsea L., Kochanek, Christopher S., Agol, Eric
We present the first resolved mid-IR (11 micron) observations of the four-image quasar lens H1413+117 using the Michelle camera on Gemini North. All previous observations (optical, near-IR, and...
The Star Formation and Nuclear Accretion Histories of Normal Galaxies in the AGES Survey (2009)
Watson, Casey R., Kochanek, Christopher S., Forman, William R., Hickox, Ryan C., Jones, Christine J., Brown, Michael J. I., ...
We combine IR, optical and X-ray data from the overlapping, 9.3 square degree NOAO Deep Wide-Field Survey (NDWFS), AGN and Galaxy Evolution Survey (AGES), and XBootes Survey to measure the X-ray...
The origin of the 24 μm excess in red galaxies (2009)
Brand, Kate, Moustakas, John, Armus, Lee, Assef, Roberto J., Brown, Michael J. I., Cool, Richard R., ...
Observations with the Spitzer Space Telescope have revealed a population of red sequence galaxies with a significant excess in their 24 μm emission compared to what is expected from an old stellar...
Hickox, Ryan C., Jones, Christine, Forman, William R., Murray, Stephen S., Kochanek, Christopher S., Eisenstein, Daniel, ...
We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of...
The Origin of the 24-micron Excess in Red Galaxies (2008)
Brand, Kate, Moustakas, John, Armus, Lee, Assef, Roberto J., Brown, Michael J. I., Cool, Richard R., ...
Observations with the Spitzer Space Telescope have revealed a population of red-sequence galaxies with a significant excess in their 24-micron emission compared to what is expected from an old...
A New Class of Luminous Transients and A First Census of Their Massive Stellar Progenitors (2008)
Thompson, Todd A., Prieto, Jose L., Stanek, K. Z., Kistler, Matthew D., Beacom, John F., Kochanek, Christopher S.
The progenitors of SN 2008S and the luminous 2008 transient in NGC 300 were dust-enshrouded, with extremely red mid-infrared (MIR) colors. In addition, the MIR luminosities of the M85 transient and...
Inada, Naohisa, Oguri, Masamune, Falco, Emilio E., Broadhurst, Tom J., Ofek, Eran O., Kochanek, Christopher S., ...
We present the results of deep spectroscopy for the central region of the cluster lens SDSS J1004+4112 with the Subaru telescope. A secure detection of an emission line of the faint blue stellar...
Evolution of the UV Excess in Early-Type Galaxies (2008)
Atlee, David W., Assef, Roberto J., Kochanek, Christopher S.
We examine the UV emission from luminous early-type galaxies as a function of redshift. We perform a stacking analysis using Galaxy Evolution Explorer (GALEX) images of galaxies in the NOAO Deep Wide...
The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) (2008)
Moustakas, Leonidas A, Bolton, Adam J, Booth, Jeffrey T, Bullock, James S, Cheng, Edward, Coe, Dan, ...
(abridged) The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) is a mission concept for a 1.5-m near-UV through near-IR space observatory that will be dedicated to frequent...
The third image of the large-separation lensed quasar SDSS J1029+26231 (2008)
Oguri, Masamune, Ofek, Eran O., Inada, Naohisa, Morokuma, Tomoki, Falco, Emilio E., Kochanek, Christopher S., ...
We identify a third image in the unique quasar lens SDSS J1029+2623, the second known quasar lens produced by a massive cluster of galaxies. The spectrum of the third image shows similar emission and...
Dai, Xinyu, Kochanek, Christopher S.
We analyzed Chandra observations of three gravitational lenses, SBS0909+523, FBQS0951+2635, and B1152+199, to measure the differential X-ray absorption and the dust-to-gas ratio of the lens galaxies....
X-Ray and Optical Microlensing in the Lensed Quasar PG 1115+080 (2008)
Morgan, Christopher W., Kochanek, Christopher S., Dai, Xinyu, Morgan, Nicholas D., Falco, Emilio E.
We analyzed the microlensing of the X-ray and optical emission of the lensed quasar PG 1115+080. We find that the effective radius of the X-ray emission is 1.3(+1.1 -0.5) dex smaller than that of the...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
The Third Image of the Large-Separation Lensed Quasar SDSS J1029+2623 (2008)
Oguri, Masamune, Ofek, Eran O., Inada, Naohisa, Morokuma, Tomoki, Falco, Emilio E., Kochanek, Christopher S., ...
We identify a third image in the unique quasar lens SDSS J1029+2623, the second known quasar lens produced by a massive cluster of galaxies. The spectrum of the third image shows similar emission and...
Twisting Of X-Ray Isophotes In Triaxial Galaxies (2008)
Aaron Romanowsky, Christopher S. Kochanek
We investigate X-ray isophote twists created by triaxiality differences between the luminous stellar distributions and the dark halos in elliptical galaxies. For a typically oblate luminous galaxy...
Difference Imaging of Lensed Quasar Candidates in the SDSS Supernova Survey Region (2008)
Lacki, Brian C., Kochanek, Christopher S., Stanek, Krzysztof Z., Inada, Naohisa, Oguri, Masamune
Difference imaging provides a new way to discover gravitationally lensed quasars because few non-lensed sources will show spatially extended, time variable flux. We test the method on lens candidates...
The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) (2008)
Moustakas, Leonidas A., Bolton, Adam J., Booth, Jeffrey T., Bullock, James S., Cheng, Edward, Coe, Dan, ...
Discovery of the dust-enshrouded progenitor of SN 2008S with Spitzer (2008)
Prieto, José L., Kistler, Matthew D., Thompson, Todd A., Yüksel, Hasan, Kochanek, Christopher S., Stanek, Krzysztof Z., ...
We report the discovery of the progenitor of the recent Type IIn SN 2008S in the nearby galaxy NGC 6946. Surprisingly, it was not found in deep, preexplosion optical images of its host galaxy taken...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
Dynamics Of Stars And Globular Clusters In M87 (2007)
Aaron Romanowsky Kapteyn, Aaron J. Romanowsky, Christopher S. Kochanek
We examine the dynamics of the stars and globular clusters in the nearby giant galaxy M87 and constrain the mass distribution, using all the available data over a large range of radii, including...
Cluster Aaron Romanowsky, Aaron J. Romanowsky, Christopher S. Kochanek
. We model the dynamics of the star cluster around Sgr A using a spherical potential and an arbitrary two-integral distribution function in order to fully include the uncertainties created by orbital...
Aaron J. Romanowsky Christopher S. Kochanek (2007)
F. Combes, G. A. Mamon, V. Charm, Aaron J. Romanowsky, Christopher S. Kochanek
. We examine the dynamics of the stars and globular clusters in the nearby giant galaxy M87 and constrain the mass distribution using all the available kinematical data, including higher-order...
Structural And Dynamical Uncertainties In Modeling Axisymmetric Elliptical Galaxies (2007)
Aaron J. Romanowsky, Christopher S. Kochanek
Quantitative dynamical models of galaxies require deprojecting the observed surface brightness to determine the luminosity density of the galaxy. Existing deprojection methods for axisymmetric...
From The, Aaron J. Romanowsky, Christopher S. Kochanek
We employ Schwarzschild's method of orbit modeling to constrain the mass profiles of the central lens galaxies in Q0957+561 and PG 1115+080. We combine the measured central projected stellar...
New Projections of Triaxiality (2007)
Stromlo Symposium, M. Arnaboldi, P. Saha, Aaron Romanowsky, Christopher S. Kochanek
: An elliptical galaxy is considered to consist of a triaxial luminous stellar distribution embedded in a triaxial "dark" halo. Differences in the triaxialities lead to kinematic...
DYNAMICS OF STARS AND GLOBULAR CLUSTERS IN M87 (2007)
Aaron J. Romanowsky, Christopher S. Kochanek
We examine the dynamics of the stars and globular clusters in the nearby giant elliptical galaxy M87 and constrain the mass distribution, using all the available data over a large range of radii,...
A new quadruply lensed quasar: SDSS J125107.57+293540.5 (2007)
Kayo, Issha, Inada, Naohisa, Oguri, Masamune, Hall, Patrick B., Kochanek, Christopher S., Richards, Gordon T., ...
We report the discovery of a quadruply imaged quasar, SDSS J125107.57+293540.5, selected from the Sloan Digital Sky Survey. Follow-up imaging reveals that the system consists of four blue pointlike...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
A New Quadruply Lensed Quasar: SDSSJ125107.57+293540.5 (2007)
Kayo, Issha, Inada, Naohisa, Oguri, Masamune, Hall, Patrick B., Kochanek, Christopher S., Richards, Gordon T., ...
We report the discovery of a quadruply imaged quasar, SDSSJ125107.57+293540.5, selected from the Sloan Digital Sky Survey. Follow-up imaging reveals that the system consists of four blue point-like...
Morokuma, Tomoki, Inada, Naohisa, Oguri, Masamune, Ichikawa, Shin-Ichi, Kawano, Yozo, Tokita, Kouichi, ...
We report the discovery of the two-image gravitationally lensed quasar SDSS J133222.62+034739.9 (SDSS J1332+ 0347) with an image separation of ¼1:1400. This system consists of a source quasar at zs...
Two new gravitationally lensed double quasars from the Sloan Digital Sky Survey (2007)
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Kayo, Issha, Kochanek, Christopher S., ...
We report the discoveries of the two-image gravitationally lensed quasars SDSS J074653.03+440351.3 and SDSS J140624.82+612640.9, selected from the Sloan Digital Sky Survey (SDSS). SDSS J0746+4403,...
SDSS J1029_2623: a gravitationally lensed quasar with an image separation of 22.5 inches (2006)
Inada, Naohisa, Oguri, Masamune, Morokuma, Tomoki, Doi, Mamoru, Yasuda, Naoki, Becker, Robert H., ...
We report the discovery of a cluster-scale lensed quasar, SDSS J1029+2623, selected from the Sloan Digital Sky Survey. The lens system exhibits two lensed images of a quasar at z p 2.197. The image...
Morokuma, Tomoki, Inada, Naohisa, Oguri, Masamune, Ichikawa, Shin-Ichi, Kawano, Yozo, Tokita, Kouichi, ...
We report the discovery of the two-image gravitationally lensed quasar SDSS J133222.62+034739.9 (SDSS J1332+0347) with an image separation of Delta_theta=1.14". This system consists of a source...
Two New Gravitationally Lensed Double Quasars from the Sloan Digital Sky Survey (2006)
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Kayo, Issha, Kochanek, Christopher S., ...
We report the discoveries of the two-image gravitationally lensed quasars, SDSS J0746+4403 and SDSS J1406+6126, selected from the Sloan Digital Sky Survey (SDSS). SDSS J0746+4403, which will be...
The Discovery of Three New z>5 Quasars in the AGN and Galaxy Evolution Survey (2006)
Cool, Richard J., Kochanek, Christopher S., Eisenstein, Daniel J., Stern, Daniel, Brand, Kate, Brown, Michael J. I., ...
We present the discovery of three z>5 quasars in the AGN and Galaxy Evolution Survey (AGES) spectroscopic observations of the NOAO Deep Wide-Field Survey (NDWFS) Bootes Field. These quasars were...
Peng, Chien Y., Impey, Chris D., Rix, Hans-Walter, Kochanek, Christopher S., Keeton, Charles R., Falco, Emilio E., ...
In the present-day universe, supermassive black hole masses (MBH) appear to be strongly correlated with their galaxy's bulge luminosity, among other properties. In this study we explore the analogous...
Spectroscopic redshifts for seven lens galaxies (2006)
Ofek, Eran O., Maoz, Dan, Rix, Hans-Walter, Kochanek, Christopher S., Falco, Emilio E.
The use of gravitationally lensed quasars for cosmological applications and as probes of galaxy structure and evolution requires knowledge about the lens redshift, which is unknown for a large...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Gregg, Michael D., Schechter, Paul L., ...
We report the discoveries of two, two-image gravitationally lensed quasars selected from the Sloan Digital Sky Survey: SDSS J0806+2006 at z_s=1.540 and SDSS J1353+1138 at z_s=1.629 with image...
Brown, Michael J. I., Brand, Kate, Dey, Arjun, Jannuzi, Buell T., Cool, Richard, Floc'h, Emeric Le, ...
We determine the rest-frame 8 micron luminosity function of type I quasars over the redshift range 1
Black Hole Masses and Eddington Ratios at 0.3 (2005)
Kollmeier, Juna A., Onken, Christopher A., Kochanek, Christopher S., Gould, Andrew, Weinberg, David H., Dietrich, Matthias, ...
We study the distribution of Eddington luminosity ratios, L_bol/L_edd, of active galactic nuclei (AGNs) discovered in the AGN and Galaxy Evolution Survey (AGES). We combine H-beta, MgII, and CIV line...
The Quintuple Quasar: Radio and Optical Observations (2003)
Winn, Joshua N., Kochanek, Christopher S., Keeton, Charles R., Lovell, James E. J.
We present results from high-resolution radio and optical observations of PMN J0134-0931, a gravitational lens with a unique radio morphology and an extremely red optical counterpart. Our data...