In 2009 January, the 2.1-s anomalous X-ray pulsar 1E 1547.0−5408 evoked intense burst activity. A follow-up Suzaku observation on January 28 recorded enhanced persistent emission in both soft and hard X-rays. Through a reanalysis of the same Suzaku data, 18 short bursts were identified in the X-ray events recorded by the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS). Their ...

FU Orionis objects (FUors) have undergone strong optical outbursts and are thought to be young low-mass stars accreting at high rates of up to Ṁacc ∼ 10 −4 M⊙ yr . FUors have been extensively studied at optical and infrared wavelengths, but little is known about their X-ray properties. We have thus initiated a program aimed at searching for and characterizing their X-ray emission. First results...

We present a combined radio, optical, and X-ray study of the nearby LINER galaxy NGC 1052. Data from a short (2.3 ksec) CHANDRA observation of NGC 1052 reveal the presence of various jet-related X-ray emitting regions, a bright compact core and unresolved knots in the jet structure as well as an extended emitting region inside the galaxy well aligned with the radio synchrotron jet-emission. The...

I present ASCA observations of IRAS00317-2142, the most luminous (Lx ∼ 10 43 erg s0.1-2 keV) of the ’composite’ class of galaxies. This enigmatic class of objects presents narrow-emission line optical spectra classifying these galaxies as star-forming on the basis of the diagnostic emission line ratios; yet, the presence of weak Hα broad wings also suggests the presence of a weak or obscured AG...

In 2009 January, the 2.1-s anomalous X-ray pulsar 1E 1547.0−5408 evoked intense burst activity. A follow-up Suzaku observation on January 28 recorded enhanced persistent emission in both soft and hard X-rays. Through a reanalysis of the same Suzaku data, 18 short bursts were identified in the X-ray events recorded by the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS). Their ...

We report the detection of the double neutron star binary (DNSB) B1534+12 (= J1537+1155) with the Chandra X-ray Observatory. This DNSB (Porb = 10.1 hr) consists of the millisecond (recycled) pulsar J1537+1155A (PA = 37.9 ms) and a neutron star not detected in the radio. After the remarkable double pulsar binary J0737−3039, it is the only other DNSB detected in X-rays. We measured the flux of (2...

We model an accretion disk atmosphere and corona photoionized by a central X-ray continuum source. We calculate the opacity and one-dimensional radiation transfer for an array of disk radii, to obtain the two-dimensional structure of the disk and its X-ray recombination emission. The atmospheric structure is extremely insensitive to the viscosity α. We find a feedback mechanism between the disk...

Thirteen yr observation data of 4FGL J0824.9+3915 with the Large Area Telescope on board Fermi Gamma Ray Space (Fermi/LAT) are analyzed for revisiting whether 4C +39.23B, a compact steep-spectrum (CSS) source closed to flat-spectrum radio quasar (FSRQ) +39.23A in $\gamma$-ray emitting region J0824.9+3915, is emitter. We find that time-integrated emission overwhelmingly dominated by +39.23A. It ...

We report the rst pointed X{ray observation, made by ASCA, of the nearby Seyfert 2 galaxy in Circinus. The spectrum consists of a very prominent (EW2 keV) uorescent 6.4 keV iron line, a very at continuum (photon spectral index less than one) and other lines, including one at 7 keV probably due, at least in part, to iron K uorescent emission. The spectrum is consistent with Compton scattering an...

We have used a deep Chandra observation of the central regions of the twin-jet FRI radio galaxy 3C 31 to resolve the thermal X-ray emission in the central few kiloparsecs of the host galaxy, NGC 383, where the jets are thought to be decelerating rapidly. This allows us to make high-precision measurements of the density, temperature and pressure distributions in this region, and to show that the...