Publications (59)
Hard X-ray Variability in M82: Evidence for a Nascent AGN?
A. Ptak, R. Griffiths
An Extremely Luminous and Variable Ultraluminous X-ray Source in the Outskirts of Circinus Observed with NuSTAR
D. J. Walton, F. Fuerst, F. A. Harrison +16
SHEEP: The Search for the High Energy Extragalactic Population
K. Nandra, I. Georgantopoulos, A. Ptak +1
Exploring the Connection Between Star Formation and AGN Activity in the Local Universe
Stephanie M. LaMassa, T. M. Heckman, A. Ptak +3
The growth and evolution of super massive black holes
S. Murray, R. Gilli, P. Tozzi +19
X-ray Luminosity Functions of Normal Galaxies in the GOODS
A. Ptak, B. Mobasher, A. Hornschemeier +2
Testing Radiatively-Inefficient Accretion Flow Theory: an XMM-Newton Observation of NGC 3998
A. Ptak, Y. Terashima, L. C. Ho +1
X-ray Constraints on Accretion and Starburst Processes in Galactic Nuclei I. Spectral Results
A. Ptak, P. Serlemitsos, T. Yaqoob +1
Simulating the WFXT sky
P. Tozzi, J. Santos, H. Yu +9
A Chandra Survey of the Nearest ULIRGs: Obscured AGN or Super-Starbursts?
A. Ptak, T. Heckman, N. A. Levenson +2
Optical Counterparts of Ultra-Luminous X-ray Sources identified from Archival Hubble Space Telescope/WFPC2
A. Ptak, E. Colbert, R. Van der Marel +3
Identification of the Hard X-ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31
M. Yukita, A. Ptak, A. E. Hornschemeier +15
Wide Field X-ray Telescope: Mission Overview
P. Rosati, S. Borgani, R. Gilli +9
Modeling X-ray binary evolution in normal galaxies: Insights from SINGS
P. Tzanavaris, T. Fragos, M. Tremmel +7
Chandra and XMM Observations of Type II Quasars from the SDSS
A. Ptak, N. Zakamska, M. Strauss +4
The 4 Ms Chandra Deep Field-South Number Counts Apportioned by Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies
B. D. Lehmer, Y. Q. Xue, W. N. Brandt +13
Broadband X-ray Spectra of the Ultraluminous X-ray Source Holmberg IX X-1 observed with NuSTAR, XMM-Newton and Suzaku
D. J. Walton, F. A. Harrison, B. W. Grefenstette +16
The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
A. Markowitz, T. Takahashi, S. Watanabe +16
Resolving the X-ray Spectral Paradox: XMM-Newton Spectra of Faint Sources in the Lockman Hole
R. E. Griffiths, A. Ptak, T. Miyaji
Disentangling AGN and Star Formation in Soft X-rays
Stephanie M. LaMassa, T. M. Heckman, A. Ptak
Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13
F. Fuerst, D. J. Walton, F. A. Harrison +12
XAssist: A System for the Automation of X-ray Astrophysics Analysis
A. Ptak, R. Griffiths
A long hard-X-ray look at the dual active galactic nuclei of M51 with NuSTAR
M. Brightman, M. BalokoviÄ, M. Koss +14
Local Lyman Break Galaxy Analogs: The Impact of Massive Star-forming Clumps on the Interstellar Medium and the Global Structure of Young, Forming Galaxies
R. A. Overzier, T. M. Heckman, C. Tremonti +10
A Simple New Method For Analysing Gapped Time-Series: Search For a High Frequency Cut-off In The X-ray Power Spectrum of MCG -6-30-15
T. Yaqoob, B. McKernan, A. Ptak +2
SHEEP: the ASCA 5-10 keV survey
I. Georgantopoulos, K. Nandra, A. Ptak
Feedback in the local LBG Analog Haro 11 as probed by far-UV and X-ray observations
J. P. Grimes, T. Heckman, D. Strickland +6
On the Spatially Resolved Star-Formation History in M51 II: X-ray Binary Population Evolution
B. D. Lehmer, R. T Eufrasio, L. Markwardt +7
Galaxy clusters and the cosmic cycle of baryons across cosmic times
R. Giacconi, S. Borgani, P. Rosati +18
Wide Area X-ray Surveys for AGN and Starburst Galaxies
A. Ptak
X-ray Variability as a Probe of Advection-Dominated Accretion in Low-Luminosity AGN
A. Ptak, T. Yaqoob, R. Mushotzky +2
A Compton-thick AGN at z~5 in the 4 Ms Chandra Deep Field South
R. Gilli, J. Su, C. Norman +13
The Very Local Universe in X-rays
A. Ptak, E. Feigelson, Y. -H. Chu +25
The 0.3-30 keV Spectra of Powerful Starburst Galaxies: NuSTAR and Chandra Observations of NGC 3256 and NGC 3310
B. D. Lehmer, J. B. Tyler, A. E. Hornschemeier +13
The Statistical Properties of Galaxies Containing ULXs
A. Ptak, E. Colbert
A Focused, Hard X-ray Look at Arp 299 with NuSTAR
A. Ptak, A. Hornschemeier, A. Zezas +19
Modeling the Redshift Evolution of the Normal Galaxy X-ray Luminosity Function
M. Tremmel, T. Fragos, B. D. Lehmer +9
Decoupling absorption and continuum variability in the Seyfert 2 NGC 4507
V. Braito, L. Ballo, J. N. Reeves +3
X-ray Cluster Cosmology
A. Vikhlinin, S. Murray, R. Gilli +18
The Relationship of Hard X-ray and Optical Line Emission in Low Redshift Active Galactic Nuclei
T. M. Heckman, A. Ptak, A. Hornschemeier +1
The X-ray Spectral Variability of the Seyfert Galaxy NGC 3227
I. M. George, R. F. Mushotzky, T. J. Turner +4
Young Accreting Compact Objects in M31: The Combined Power of NuSTAR, Chandra, and Hubble
M. Lazzarini, A. E. Hornschemeier, B. F. Williams +11
The Broadband Spectral Variability of Holmberg IX X-1
D. J. Walton, F. Fuerst, F. A. Harrison +9
Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
Y. Ishisaki, Y. Maeda, R. Fujimoto +31
On the Spatially Resolved Star Formation History in M51 I: Hybrid UV+IR Star Formation Laws and IR Emission from Dust Heated by Old Stars
R. T. Eufrasio, B. D. Lehmer, A. Zezas +10
The Consequences of the Cosmic Star-Formation Rate: X-ray Number Counts
A. Ptak, R. Griffiths, N. White +1
Uncovering Obscured Active Galactic Nuclei in Homogeneously Selected Samples of Seyfert 2 Galaxies
Stephanie M. LaMassa, T. M. Heckman, A. Ptak +4
A Peculiar Emission Line Feature in the X-ray Spectrum of the Quasar PKS 0637-752
T. Yaqoob, I. M. George, T. J. Turner +3
A Hard X-ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR
M. Yukita, A. E. Hornschemeier, B. D. Lehmer +19
The Complex X-ray Spectra of M82 and NGC 253
A. Ptak, P. Serlemitsos, T. Yaqoob +2
A Suzaku observation of the ULIRG IRAS19254-7245: disclosing the AGN component
V. Braito, J. N. Reeves, R. Della Ceca +3
A Catalog of Candidate Intermediate-luminosity X-ray Objects
E. Colbert, A. Ptak
A Chandra X-ray Investigation of the Violent Interstellar Medium: From Dwarf Starbursts to Ultraluminous Infrared Galaxies
J. P. Grimes, T. Heckman, D. Strickland +1
Low-luminosity AGN and Normal Galaxies
A. Ptak
Far-Ultraviolet & X-ray Observations of VV 114: Feedback in a Local Analog to Lyman Break Galaxies
J. P. Grimes, T. Heckman, C. Hoopes +4
Super-Eddington Accretion onto the Neutron Star NGC 7793 P13: Broadband X-ray Spectroscopy and Ultraluminous X-ray Sources
D. J. Walton, F. Fuerst, F. A. Harrison +8
XMM-Newton observations of NGC 253: Resolving the emission components in the disk and nuclear area
W. Pietsch, T. P. Roberts, M. J. Freyberg +11
X-ray Observations of LINER and Starburst Galaxies
P. Serlemitsos, A. Ptak, T. Yaqoob
A search for AGN in the most extreme UV-selected starbursts using the European VLBI Network
R. Alexandroff, R. A. Overzier, Z. Paragi +7