相关论文: Shedding light on the nature of ESO 243-49 HLX-1

LS 5039 is a relatively close microquasar consisting of a late O-type star and a compact object (very possibly a black hole) on a highly eccentric orbit with a period of 3.9 days. The high X-ray, gamma-ray and radio luminosity indicate…

Optical counterparts can provide significant constraints on the physical nature of ultraluminous X-ray sources (ULXs). In this letter, we identify six point sources in the error circle of a ULX in M82, namely M82 X-1, by registering Chandra…

We present a reanalysis of the EHT 228 GHz observations of M87. We apply traditional hybrid mapping techniques to the publicly available `network-calibrated' data. We explore the impact on the final image of different starting models,…

We present new medium resolution, optical long-slit spectra of a sample of 6 UV/optical and 15 X-ray selected tidal disruption event candidate host galaxies. We measure emission line ratios from the optical spectra, finding that the large…

We report on Chandra observations of the bright ultra-luminous X-ray (ULX) source in NGC3921. Previous XMM observations reported in the literature show the presence of a bright ULX at a 0.5-10 keV luminosity of 2x10^40 erg/s. Our Chandra…

We present a systematic analysis of archival HST WFPC2 ``Association'' data sets that correlate with the Chandra positions of a set of 44 ultra-luminous X-ray sources (ULXs) of nearby galaxies. We have improved the Chandra-HST relative…

We present the results of optical panoramic and long-slit spectroscopy of the nebula MF16 associated with the Ultraluminous X-ray Source NGC6946 ULX-1. More than 20 new emission lines are identified in the spectra. Using characteristic line…

Ultraluminous X-ray sources (ULXs) are some of the most enigmatic X-ray bright sources known to date. It is generally accepted that they cannot host black holes as large as those associated with active galaxies, but they appear to be…

We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of HD142527 with MagAO's VisAO science camera. In the median seeing conditions of the 6.5m Magellan…

RX J0134.2-4258 is one of the most super-Eddington narrow-line Seyfert 1 (NLS1) galaxies, on which we conducted a monitoring campaign from radio to X-rays. In this paper, we present a detailed analysis of its optical/UV spectra and…

We present a systematic X-ray study, the third in a series, of 49 active galactic nuclei with intermediate-mass black holes (IMBH; ~10^5-10^6 M_sun) using Chandra observations. We detect 42 out of 49 targets with a 0.5-2 keV X-ray…

We present HST/WFPC2 broadband and ground-based Halpha images, H I 21-cm emission maps, and low-resolution optical spectra of the nearby galaxy ESO 1327-2041, which is located 38 arcsec (14 kpc in projection) west of the quasar PKS…

Holmberg IX X-1 is an archetypal ultraluminous X-ray source (ULX). Here we study the properties of the optical counterpart and of its stellar environment using optical data from SUBARU/Faint Object Camera and Spectrograph,GEMINI/GMOS-N and…

We implement a standard thin disk model with the outer disk radius ($R_{\rm out}$) as a free parameter, integrating it into standard X-ray fitting package to enable self-consistent and simultaneous fitting of X-ray spectra and…

We derive the luminosity-temperature relation for the super-critically accreting black holes (BHs) and compare it to the data on ultraluminous X-ray sources (ULXs). At super-Eddington accretion rates, an outflow forms within the…

We present Hubble Space Telescope (HST) observations of the field of the Type IIb supernova (SN) 2011dh in M51 performed at ~1161 rest-frame days after explosion using the Wide Field Camera 3 and near-UV filters F225W and F336W. A star-like…

We present a detailed multi-wavelength study of an unobscured, highly super-Eddington Type-1 QSO RX J0439.6-5311. We combine the latest XMM-Newton observation with all archival data from infrared to hard X-rays. The optical spectrum is very…

Stellar collapse models predict that some stars more massive than $\sim$15$M_\odot$ may collapse directly to a black hole, sometimes with a weak optical transient, a phenomenon known as a failed supernova. Detecting such events is…

We present initial results from observations of the low-mass X-ray binary EXO 0748-67 with the Reflection Grating Spectrometer on board the XMM-Newton Observatory. The spectra exhibit discrete structure due to absorption and emission from…

Observations of the Ultra Luminous X-ray source (ULX) Holmberg IX X-1 were carried out with Suzaku twice, once on 2012 April 13 and then on 2012 October 24, with exposures of 180 ks and 217 ks, respectively. The source showed a hard…