Publications (26)
Measuring the Accreting Stellar and Intermediate Mass Black Hole Populations in the Galaxy and Local Group
Jonathan Grindlay, Didier Barret, Tomaso Belloni +23
The population of stellar black holes (SBHs) in the Galaxy and galaxies generally is poorly known in both number and distribution. SBHs are the fossil record of the massive stars i…
Dominance of Magnetic Cataclysmic Variables in the Resolved Galactic Ridge X-ray Emission of the Limiting Window
JaeSub Hong
The diffuse appearance of the Galactic Ridge X-ray Emission (GRXE) has been puzzling since its discovery due to lack of compelling theories for sustainable hot diffuse X-ray emissi…
ChaMPlane Optical Survey: Mosaic Photometry
Ping Zhao, Jonathan E. Grindlay, JaeSub Hong +4
The ChaMPlane survey to identify and analyze the serendipitous X-ray sources in deep Galactic plane fields incorporates the ChaMPlane Optical Survey, which is one of NOAO's Long-te…
Discovery of a Significant Magnetic CV Population in the Limiting Window
JaeSub Hong, Maureen van den Berg, Jonathan E. Grindlay +2
[Abridged] We have discovered 10 periodic X-ray sources from the 1 Ms Chandra ACIS observation of the Limiting Window (LW), a low extinction region (A_V~3.9) at 1.4 Deg south of th…
Instability of the 13.8 day period in X-ray emission from 4U1700-377
JaeSub Hong, Charles J. Hailey
We present a new result on long-term periodicity searches of the X-ray emission from 4U1700-377 using RXTE ASM and CGRO BATSE data. The hard X-ray data (20 - 200 keV) from early BA…
A multiwavelength study of the Galactic center black hole candidate MAXI J1744-294
Shifra Mandel, Kaya Mori, Paul A. Draghis +37
For the first time in nearly a decade, a bright transient was detected in the central parsec (pc) of the Galaxy. MAXI J1744-294, or -- as it was known in its previous life -- Swift…
Chandra Observations of NuSTAR Serendipitous Sources near the Galactic Plane
John A. Tomsick, George B. Lansbury, Farid Rahoui +8
The NuSTAR serendipitous survey has already uncovered a large number of Active Galactic Nuclei (AGN), providing new information about the composition of the Cosmic X-ray Background…
Chandra Multi-wavelength Plane (ChaMPlane) Survey: Design and Initial Results
Jonathan Grindlay, Ping Zhao, JaeSub Hong +9
The Chandra Multiwavength Plane (ChaMPlane) Survey of the galactic plane incorporates serendipitous sources from selected Chandra pointings in or near the galactic plane (b < 12deg…
Investigating the origin of the faint non-thermal emission of the Arches cluster using the 2015-2016 NuSTAR and XMM-Newton X-ray observations
Ekaterina Kuznetsova, Roman Krivonos, Maïca Clavel +7
Recent NuSTAR and XMM-Newton observations of the molecular cloud around the Arches stellar cluster demonstrate a dramatic change both in morphology and intensity of its non-thermal…
The ChaMPlane bright X-ray sources - Galactic longitudes l = 2-358 deg
Maureen van den Berg, Kyle Penner, JaeSub Hong +4
The Chandra Multiwavelength Plane (ChaMPlane) Survey aims to constrain the Galactic population of mainly accretion-powered, but also coronal, low-luminosity X-ray sources (Lx <~ 1e…
ChaMPlane Deep Galactic Bulge Survey. I. Faint accretion-driven binaries in the Limiting Window
Maureen van den Berg, JaeSub Hong, Jonathan E. Grindlay
[Abridged] We have carried out a deep X-ray and optical survey with Chandra and HST of low-extinction regions in the Galactic bulge. Here we present the results of a search for low…
Hunting for High-Mass X-ray Binaries in the Galactic Center with NuSTAR
Shifra Mandel, Julian Gerber, Kaya Mori +9
The central deg region of our Galaxy contains X-ray point sources that were detected by a series of Chandra observations over the last two decades. Ho…
Anti-correlation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
Jun Yang, Andreas Zezas, Malcolm J. Coe +4
We report the evidence for the anti-correlation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range --…
Investigating ChaMPlane X-ray sources in the Galactic Bulge with Magellan LDSS2 spectra
Xavier Koenig, Jonathan E. Grindlay, Maureen van den Berg +4
We have carried out optical and X-ray spectral analyses on a sample of 136 candidate optical counterparts of X-ray sources found in five Galactic-bulge fields included in our Chand…
Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-ray Pulsars
JaeSub Hong, Vallia Antoniou, Andreas Zezas +5
We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We have analyzed a total exposure of 1.4 Ms from 31 ob…
NuSTAR and XMM-Newton observations of the Arches cluster in 2015: fading hard X-ray emission from the molecular cloud
Roman Krivonos, Maica Clavel, JaeSub Hong +6
We present results of long NuSTAR (200 ks) and XMM-Newton (100 ks) observations of the Arches stellar cluster, a source of bright thermal (kT~2 keV) X-rays with prominent Fe XXV K_…
Galactic Sources Detected in the NuSTAR Serendipitous Survey
John A. Tomsick, George B. Lansbury, Farid Rahoui +13
The Nuclear Spectroscopic Telescope Array (NuSTAR) provides an improvement in sensitivity at energies above 10 keV by two orders of magnitude over non-focusing satellites, making i…
The NuSTAR Hard X-ray Survey of the Norma Arm Region
Francesca M. Fornasini, John A. Tomsick, JaeSub Hong +32
We present a catalog of hard X-ray sources in a square-degree region surveyed by NuSTAR in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, a…
The Brightest Serendipitous X-ray Sources in ChaMPlane
Kyle Penner, Maureen van den Berg, JaeSub Hong +3
The Chandra Multiwavelength Plane (ChaMPlane) Survey is a comprehensive effort to constrain the population of accretion-powered and coronal low-luminosity X-ray sources (L_X < 10^3…
NuSTAR Hard X-ray Survey of the Galactic Center Region II: X-ray Point Sources
JaeSub Hong, Kaya Mori, Charles J. Hailey +41
We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg…
Chandra Discovery of an Intermediate Polar in Baade's Window
JaeSub Hong, Maureen van den Berg, Silas Laycock +2
(Abridged) We have discovered an intermediate polar (IP) in the 100 ks Chandra observation of Baade's Window (BW), a low extinction region at ~ 4 deg south of the Galactic Center.…
X-ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti-Galactic Center Fields
JaeSub Hong, Maureen van den Berg, Eric M. Schlegel +4
We describe the X-ray analysis procedure of the on-going Chandra Multiwavelength Plane (ChaMPlane) survey and report the initial results from the analysis of 15 selected anti-Galac…
Photon Folding for Imaging in Non-Focusing Telescopes
JaeSub Hong
We present a new technique - photon folding - for imaging in non-focusing telescopes. Motivated by the epoch-folding method in timing analysis, the photon folding technique directl…
The Dynamic X-ray Sky of the Local Universe
Alicia M. Soderberg, Jonathan E. Grindlay, Joshua S. Bloom +35
Over the next decade, we can expect time domain astronomy to flourish at optical and radio wavelengths. In parallel with these efforts, a dedicated transient "machine" operating at…
First hard X-ray detection of the non-thermal emission around the Arches cluster: morphology and spectral studies with NuSTAR
Roman A. Krivonos, John A. Tomsick, Franz E. Bauer +15
The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray em…
SXP214, an X-ray Pulsar in the Small Magellanic Cloud, Crossing the Circumstellar Disk of the Companion
JaeSub Hong, Vallia Antoniou, Andreas Zezas +12
Located in the Small Magellanic Cloud (SMC), SXP214 is an X-ray pulsar in a high mass X-ray binary system with a Be-star companion. A recent survey of the SMC under a Chandra X-ray…