Browsing FAS Scholarly Articles by Title

Now showing items 1895-1914 of 18295

    • Chandra Exposes the Core Collapsed Globular Cluster NGC 6397 

      Grindlay, J. E.; Heinke, C. O.; Edmonds, P. D.; Murray, S. S.; Cool, A. M.; Grindlay, J.; Heinke, C.; Edmonds, P.; Murray, S.; Cool, A. (American Astronomical Society, 2001)
      We report results of the Chandra deep-imaging observation of the closest post-core-collapse globular cluster, NGC 6397. Some 25 sources are detected within 2' of the cluster center, of which similar to 20 are likely cluster ...

    • The Chandra Multi-wavelength Project: Optical Spectroscopy and the Broadband Spectral Energy Distributions of X-Ray-selected AGNs. 

      Trichas, Markos; Green, Paul J.; Silverman, John D.; Aldcroft, Tom; Barkhouse, Wayne; Cameron, Robert A.; Constantin, Anca; Ellison, Sara L.; Foltz, Craig; Haggard, Daryl; Jannuzi, Buell T.; Kim, Dong-Woo; Marshall, Herman L.; Mossman, Amy E.; Pérez, Laura M.; Romero-Colmenero, Encarni; Ruiz, Angel; Smith, Malcolm G.; Smith, Paul S.; Torres, Guillermo; Wik, Daniel R.; Wilkes, Belinda Jane; Wolfgang, Angie (IOP Publishing, 2012)
      From optical spectroscopy of X-ray sources observed as part of ChaMP, we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow up using the FLWO, SAAO, WIYN, CTIO, ...

    • Chandra Multiwavelength Plane (ChaMPlane) Survey: An Introduction 

      Grindlay, J. E.; Hong, J.; Zhao, P.; Laycock, S.; van den Berg, M.; Koenig, X.; Schlegel, E. M.; Cohn, H. N.; Lugger, P. M.; Rogel, A. B. (American Astronomical Society, 2005)
      We introduce the Chandra Multiwavelength Plane (ChaMPlane) survey, designed to measure or constrain the populations of low-luminosity (L-X greater than or similar to 10(31) ergs s(-1)) accreting white dwarfs, neutron stars, ...

    • Chandra Multiwavelength Project X‐Ray Point Source Catalog 

      Kim, Minsun; Kim, Dong‐Woo; Wilkes, Belinda Jane; Green, Paul J.; Kim, Eunhyeuk; Anderson, Craig Stephen; Barkhouse, Wayne A.; Evans, Nancy Remage; Ivezi?, ?eljko; Karovska Neily, Margarita; Kashyap, Vinay L.; Lee, Myung Gyoon; Maksym, W. Peter; Mossman, Amy E.; Silverman, John D.; Tananbaum, Harvey D. (IOP Publishing, 2007)
      We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 X-ray sources detected in 149 Chandra observations covering ~10 deg2. The full ChaMP catalog sample is 7 times larger than the ...

    • Chandra Multiwavelength Project X‐Ray Point Source Number Counts and the Cosmic X‐Ray Background 

      Kim, Minsun; Wilkes, Belinda Jane; Kim, Dong‐Woo; Green, Paul J.; Barkhouse, Wayne A.; Lee, Myung Gyoon; Silverman, John D.; Tananbaum, Harvey D. (IOP Publishing, 2007)
      We present the Chandra Multiwavelength Project (ChaMP) X-ray point source number counts and cosmic X-ray background (CXRB) flux densities in multiple energy bands. From the ChaMP X-ray point source catalog, ~5500 sources ...

    • Chandra Multiwavelength Project. I. First X‐Ray Source Catalog 

      Kim, D.‐W.; Cameron, R. A.; Drake, Jeremy J.; Evans, Nancy Remage; Freeman, P.; Gaetz, Terrance J.; Ghosh, H.; Green, P. J.; Harnden, F. R. Jr.; Karovska Neily, Margarita; Kashyap, Vinay L.; Maksym, W. Peter; Ratzlaff, Peter W; Schlegel, E. M.; Silverman, J. D.; Tananbaum, Harvey D.; Vikhlinin, Alexey A.; Wilkes, Belinda Jane; Grimes, J. P. (IOP Publishing, 2004)
      The Chandra Multiwavelength Project (ChaMP) is a wide-area (~14 deg2) survey of serendipitous Chandra X-ray sources, aiming to establish fair statistical samples covering a wide range of characteristics (such as absorbed ...

    • Chandra Multiwavelength Project. II. First Results of X‐Ray Source Properties 

      Kim, D.‐W.; Wilkes, Belinda Jane; Green, P. J.; Cameron, R. A.; Drake, Jeremy J.; Evans, Nancy Remage; Freeman, P.; Gaetz, Terrance J.; Ghosh, H.; Harnden, F. R. Jr.; Karovska Neily, Margarita; Kashyap, Vinay L.; Maksym, W. Peter; Ratzlaff, Peter W; Schlegel, E. M.; Silverman, J. D.; Tananbaum, Harvey D.; Vikhlinin, Alexey A. (IOP Publishing, 2004)
      The Chandra Multiwavelength Project (ChaMP) is a wide-area (~14 deg2) survey of serendipitous Chandra X-ray sources, aiming to establish fair statistical samples covering a wide range of characteristics (such as absorbed ...

    • Chandra Multiwavelength Project: Normal Galaxies at Intermediate Redshift 

      Kim, D.‐W.; Barkhouse, W. A.; Romero‐Colmenero, E.; Green, P. J.; Kim, M.; Mossman, Amy E.; Schlegel, E.; Silverman, J. D.; Aldcroft, Thomas L.; Anderson, C.; Ivezic, Z.; Kashyap, V.; Tananbaum, Harvey D.; Wilkes, Belinda Jane (IOP Publishing, 2006)
      We have investigated 136 Chandra extragalactic sources, including 93 galaxies with narrow emission lines (NELGs) and 43 with only absorption lines (ALGs). Based on fX/fO, LX, X-ray spectral hardness, and optical emission-line ...

    • The Chandra Multiwavelength Project: Optical Follow‐up of Serendipitous Chandra Sources 

      Green, P. J.; Silverman, J. D.; Cameron, R. A.; Kim, D.‐W.; Wilkes, Belinda Jane; Barkhouse, W. A.; LaCluyze, A.; Morris, D.; Mossman, Amy E.; Ghosh, H.; Grimes, J. P.; Jannuzi, B. T.; Tananbaum, Harvey D.; Aldcroft, Thomas L.; Baldwin, J. A.; Chaffee, F. H.; Dey, A.; Dosaj, A.; Evans, Nancy Remage; Fan, X.; Foltz, C.; Gaetz, Terrance J.; Hooper, E. J.; Kashyap, Vinay L.; Mathur, S.; McGarry, M. B.; Romero‐Colmenero, E.; Smith, M. G.; Smith, P. S.; Smith, R. C.; Torres, Guillermo; Vikhlinin, Alexey A.; Wik, D. R. (IOP Publishing, 2004)
      We present follow-up optical g', r', and i' imaging and spectroscopy of serendipitous X-ray sources detected in six archival Chandra images included in the Chandra Multiwavelength Project (ChaMP). Of the 486 X-ray sources ...

    • A Chandra Observation of 3C 288—Reheating ohe Cool Core of a 3 Kev Cluster from a Nuclear Outburst at Z = 0.246 

      Lal, D. V.; Kraft, Ralph P.; Forman, William R.; Hardcastle, M. J.; Jones, C.; Nulsen, Paul; Evans, D. A.; Croston, J. H.; Lee, Julia C (IOP Publishing, 2010)
      We present results from a 42 ks Chandra/ACIS-S observation of the transitional FR I/FR II radio galaxy 3C 288 at z = 0.246. We detect ~3 keV gas extending to a radius of ~0.5 Mpc with a 0.5-2.0 keV luminosity of 6.6 × 1043 ...

    • Chandra Observation of Abell 2142: Survival of Dense Subcluster Cores in a Merger 

      Markevitch, M.; Ponman, T. J.; Nulsen, P. E. J.; Bautz, M. W.; Burke, D. J.; David, L. P.; Davis, D.; Donnelly, R. H.; Forman, W. R.; Jones, C.; Kaastra, J.; Kellogg, E.; Kim, D.-W.; Kolodziejczak, J.; Mazzotta, P.; Pagliaro, A.; Patel, S.; Van Speybroeck, L.; Vikhlinin, A.; Vrtilek, J.; Wise, M.; Zhao, P. (American Astronomical Society, 2000)
      We use Chandra data to map the gas temperature in the central region of the merging cluster A2142. The cluster is markedly nonisothermal; it appears that the central cooling flow has been disturbed but not destroyed by a ...

    • Chandra Observations of the 'Dark' Moon and Geocoronal Solar Wind Charge Transfer 

      Wargelin, B. J.; Markevitch, M.; Juda, M.; Kharchenko, V.; Edgar, R.; Dalgarno, A. (American Astronomical Society, 2004)
      We have analyzed data from two sets of calibration observations of the Moon made by the Chandra X-Ray Observatory. In addition to obtaining a spectrum of the bright side that shows several distinct fluorescence lines, we ...

    • Chandra Study of an Overdensity of X-Ray Sources around Two Distant (z ~ 0.5) Clusters 

      Cappi, M.; Mazzotta, P.; Elvis, Martin S.; Burke, D. J.; Comastri, A.; Fiore, F.; Forman, William R.; Fruscione, Antonella; Green, P.; Harris, D.; Hooper, E. J.; Jones, C.; Kaastra, J. S.; Kellogg, E.; Murray, S.; McNamara, Brian David; Nicastro, F.; Ponman, T. J.; Schlegel, E. M.; Siemiginowska, Aneta L.; Tananbaum, Harvey D.; Vikhlinin, Alexey A.; Virani, S.; Wilkes, Belinda Jane (IOP Publishing, 2001)
      We present results from a Chandra X-Ray Observatory study of the field X-ray source populations in four different observations: two high-redshift (z ~ 0.5) clusters of galaxies 3C 295 and RX J003033.2+261819; and two ...

    • A Chandra Survey of Broad Absorption Line Quasars 

      Green, Paul J.; Aldcroft, Thomas L.; Mathur, Smita; Wilkes, Belinda Jane; Elvis, Martin (IOP Publishing, 2001)
      We have carried out a survey with the Chandra X-Ray Observatory of a sample of 10 bright broad absorption line (BAL) quasars (QSOs). Eight of 10 sources are detected. The six brightest sources have only high-ionization ...

    • The Chandra Survey of Extragalactic Sources in the 3cr Catalog: X-Ray Emission From Nuclei, Jets, and Hotspots in the Chandra Archival Observations 

      Massaro, F.; Harris, D. E.; Liuzzo, E.; Orienti, M.; Paladino, R.; Paggi, A.; Tremblay, G. R.; Wilkes, Belinda Jane; Kuraszkiewicz, Joanna; Baum, S. A.; O’Dea, C. P. (IOP Publishing, 2015)
      As part of our program to build a complete radio and X-ray database of all Third Cambridge catalog extragalactic radio sources, we present an analysis of 93 sources for which Chandra archival data are available. Most of ...

    • Chandra X-ray Observations of 12 Millisecond Pulsars in the Globular Cluster M28 

      Bogdanov, Slavko; van den Berg, Maureen; Servillat, Mathieu; Heinke, Craig O.; Grindlay, Jonathan E.; Stairs, Ingrid H.; Ransom, Scott M.; Freire, Paulo C. C.; Bégin, Steve; Becker, Werner (American Astronomical Society, 2011)
      We present a Chandra X-ray Observatory investigation of the millisecond pulsars in the globular cluster M28 (NGC 6626). In what is one of the deepest X-ray observations of a globular cluster, we firmly detect seven and ...

    • Chandra X-Ray Observations of the Redshift 1.53 Radio-Loud Quasar 3c 270.1 

      Wilkes, Belinda Jane; Lal, Dharam V.; Worrall, Diana M.; Birkinshaw, Mark; Haas, Martin; Willner, Steven P.; Antonucci, Robert; Ashby, Matthew L N; Avara, Mark; Barthel, Peter; Chini, Rolf; Fazio, Giovanni Gene; Hardcastle, Martin; Lawrence, Charles; Leipski, Christian; Ogle, Patrick; Schulz, Bernhard (IOP Publishing, 2012)
      Chandra X-ray observations of the high redshift (z = 1.532) radio-loud quasar 3C 270.1 in 2008 February show the nucleus to have a power-law spectrum, Γ = 1.66 ± 0.08, typical of a radio-loud quasar, and a marginally ...

    • Chandra x-ray sources in the collapsed-core globular cluster M30 (NGC 7099) 

      Lugger, Phyllis M.; Cohn, Haldan N.; Heinke, Craig O.; Grindlay, Jonathan E.; Edmonds, Peter D. (American Astronomical Society, 2007)
      We report the detection of six discrete, low-luminosity (L-X < 10(33) ergs s(-1)) X- ray sources, located within 12" of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within ...

    • Chandra X‐Ray Observations of 19 Millisecond Pulsars in the Globular Cluster 47 Tucanae 

      Bogdanov, Slavko; Grindlay, Jonathan E.; Heinke, Craig O.; Camilo, Fernando; Freire, Paulo C. C.; Becker, Werner (American Astronomical Society, 2006)
      We present spectral and long-timescale variability analyses of Chandra X-Ray Observatory ACIS-S observations of the 19 millisecond pulsars (MSPs) with precisely known positions in the globular cluster 47 Tucanae. The X-ray ...

    • Chandra X‐Ray Observatory Observations of the Globular Cluster M28 and Its Millisecond Pulsar PSR B1821−24 

      Becker, Werner; Swartz, Douglas A.; Pavlov, George G.; Elsner, Ronald F.; Grindlay, Jonathan; Mignani, Roberto; Tennant, Allyn F.; Backer, Don; Pulone, Luigi; Testa, Vincenzo; Weisskopf, Martin C. (American Astronomical Society, 2003)
      We report here the results of the first Chandra X- Ray Observatory observations of the globular cluster M28 ( NGC 6626). We detect 46 X- ray sources, of which 12 lie within 1 core radius of the center. We show that the ...