Related papers: A parsec scale X-ray extended structure from the X…
The eastern tip region of the Carina Nebula was observed with the Suzaku XIS for 77 ks to conduct a high-precision spectral study of extended X-ray emission. XMM-Newton EPIC data of this region were also utilized to detect point sources.…
We present a 200 ks Chandra ACIS-I image of Cygnus A, and discuss a long linear feature seen in its counterlobe. This feature has a non-thermal spectrum and lies on the line connecting the brighter hotspot on the approaching side and the…
I have carried out a project to study the eccentric neutron-star binary Circinus X-1 through an extensive series of observational studies with the Rossi X-ray Timing Explorer satellite and through theoretical computer models I developed to…
Accreting black holes are thought to emit the bulk of their power in the X-ray band by releasing the gravitational potential energy of the infalling matter. At the same time, they are capable of producing highly collimated jets of energy…
We present new X-ray and optical spectroscopy of a Type 2 quasar candidate selected from a follow-up program of hard, optically-dim, serendipitous Chandra sources. The source is confirmed to be a Type 2 quasar at z=0.536 with an intrinsic…
Relativistic jets powered by stellar mass black holes in X-ray binaries appear to come in two types: steady outflows associated with hard X-ray states and large scale discrete ejections associated with transient outbursts. We show that the…
We present almost-simultaneous detections of Cygnus X-1 in the radio and mm regimes, obtained during the low/hard X-ray state. The source displays a flat spectrum between 2 and 220 GHz, with a spectral index flatter than 0.15 (3sigma).…
A deep (98.2 ks) Chandra Cycle-1 observation has revealed a wealth of discrete X-ray sources as well as diffuse emission in the nearby face-on spiral galaxy M101. From this rich dataset we have created a catalog of the 110 sources from the…
The ejection of a relativistic jet has been observed in the luminous Galactic low mass X-ray binary Cygnus X-2. Using high resolution radio observations, a directly resolved ejection event has been discovered while the source was on the…
Six x-ray point sources, with luminosities of $4 \times 10^{38} - 2 \times 10^{39} \rm ergs s^{-1}$ in the 0.4--7 keV band, were detected in Chandra observations of the spiral galaxy M100. One source is identified with supernova SN 1979C…
We report Chandra ACIS and quasi-simultaneous RXTE observations of the nearby, powerful radio galaxy Cygnus A, with the present paper focusing on the properties of the active nucleus. In the Chandra observation, the hard (> a few keV) X-ray…
We report Chandra ACIS observations of the fields of 4 QSOs showing strong extended optical emission-line regions. Two of these show no evidence for significant extended X-ray emission. The remaining two fields, those of 3C 249.1 and 4C…
We report our analysis of X-ray data on M101 ULX-1, concentrating on high state Chandra and XMM-Newton observations. We find that the high state of M101 ULX-1 may have a preferred recurrence timescale. If so, the underlying clock may have…
We present Chandra and XMM-Newton observations of the composite star-forming/Seyfert galaxy IRAS20051-1117. The X-ray imaging and spectral properties reveal the presence of an active nucleus. The Chandra image shows a strong nuclear point…
Unexpectedly strong X-ray emission from extragalactic radio jets on kiloparsec scales has been one of the major discoveries of Chandra, the only X-ray observatory capable of sub-arcsecond-scale imaging. The origin of this X-ray emission,…
We report on the direct observation of an extended X-ray jet in the $z$=6.1 radio-loud Active Galactic Nucleus PSO J030947.49+271757.31 from a deep Chandra X-ray observation (128 ksec). This detection represents the most distant kpc…
We present the first XRISM/Resolve observation of the persistently accreting neutron star (NS) low-mass X-ray binary Serpens X-1. The source was observed on October 17th, 2024, for approximately 350 ks of elapsed time, resulting in 171 ks…
We have made a 30 ksec Chandra observation of the redshift z=0.63 GPS quasar B2 0738+313. We detected X-ray emission from the core and have discovered a 200 kpc (projected on the sky) X-ray jet. The X-ray jet is narrow and curves, following…
We present a spectral and imaging analysis of the X-ray reflecting structure at the heart of the Circinus galaxy, investigating the innermost regions surrounding the central black hole. By studying an archival 200 ks Chandra ACIS-S…
Her X-1 is an accreting neutron star in an intermediate-mass X-ray binary. Like low-mass X-ray binaries (LMXBs), it accretes via Roche-lobe overflow, but similar to many high-mass X-ray binaries containing a neutron star, Her X-1 has a…