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17681. X-ray and radio images of SNR G351.0-5.4
ID:
ivo://CDS.VizieR/J/A+A/568/A107
Title:
X-ray and radio images of SNR G351.0-5.4
Short Name:
J/A+A/568/A107
Date:
21 Oct 2021
Publisher:
CDS
Description:
While searching the NRAO VLA Sky Survey (NVSS) for diffuse radio emission, we have serendipitously discovered extended radio emission close to the Galactic plane. The radio morphology suggests the presence of a previously unknown Galactic supernova remnant. An unclassified gamma-ray source detected by EGRET (3EG J1744-3934) is present in the same location and may stem from the interaction between high-speed particles escaping the remnant and the surrounding interstellar medium. Our aim is to confirm the presence of a previously unknown supernova remnant and to determine a possible association with the gamma-ray emission 3EG J1744-3934. We have conducted optical and radio follow-ups of the target using the Dark Energy Camera (DECam) on the Blanco telescope at Cerro Tololo Inter-American Observatory (CTIO) and the Giant Meterwave Radio Telescope (GMRT). We then combined these data with archival radio and gamma-ray observations.
17682. X-ray and radio sources in binaries
ID:
ivo://CDS.VizieR/J/BaltA/24/395
Title:
X-ray and radio sources in binaries
Short Name:
J/BaltA/24/395
Date:
21 Oct 2021
Publisher:
CDS
Description:
The goal of the present study was to compile complete list of binaries discovered at non-optical bands: X-ray binaries (XRB) and radio pulsars in binaries. Due to the lack of a unified identification system for XRB we had to select them from five principal catalogues of X-ray sources. After cross-identification and positional cross-matching, a general catalogue of 373 XRB was constructed for the first time. It contains coordinates, indication of photometric and spectroscopic binarity and extensive cross-identification. In the preparation of the catalogue, a number of XRB classification collisions were resolved, some catalogued identifiers and coordinates were corrected, and duplicated entries in the original catalogues were found.
17683. X-ray and radio sources in {rho} Oph Core A
ID:
ivo://CDS.VizieR/J/ApJ/613/393
Title:
X-ray and radio sources in {rho} Oph Core A
Short Name:
J/ApJ/613/393
Date:
21 Oct 2021
Publisher:
CDS
Description:
A 96ks Chandra X-ray observation of {rho} Ophiuchus cloud core A detected 87 sources, of which 60 were identified with counterparts at other wavelengths. Simultaneous multifrequency Very Large Array (VLA) observations detected 31 radio sources at 6cm, of which 10 were also detected by Chandra. We report new radio detections of the optically invisible IR source WLY 2-11 and the faint H{alpha} emission line star Elias 24 (class II).
17684. X-ray and UV parameters of radio-quiet quasars
ID:
ivo://CDS.VizieR/J/ApJ/657/116
Title:
X-ray and UV parameters of radio-quiet quasars
Short Name:
J/ApJ/657/116
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report new Chandra observations of seven optically faint, z~4 radio-quiet quasars (RQQs). We have combined these new observations with previous Chandra observations of RQQs to create a sample of 174 sources. These sources have 0.1<z<4.7, and 10^44^ergs/s<{nu}L_{nu}_(2500{AA})<10^48^ergs/s. The X-ray detection fraction is 90%.
17685. X-Ray Binaries Catalog
ID:
ivo://nasa.heasarc/xrbcat
Title:
X-Ray Binaries Catalog
Short Name:
XRBs
Date:
14 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
XRBCAT is a catalog of X-ray binaries, based on the van Paradijs (1996) compilation, and updated by Nick White to include all the new (mostly transient) systems discovered since then up until the last update (see below). The information in XRBCAT is basic and does not attempt to be complete. It includes the name of the source, the position, the pulse or orbital period (if one is known), the object class, a flux (a maximum and, if available, a minimum), and an optical V magnitude (if available). To reference XRBCAT, please use the following acknowledgment: &quot;This paper utilized the HEASARC XRBCAT X-ray Binary catalog&quot;. Since it is a very time consuming task to keep track of all the new sources and discoveries, there may be incomplete or missing sources. This catalog was last updated on April 22, 1998. This is a service provided by NASA HEASARC .
17686. X-ray binaries in M101 with HST optical data
ID:
ivo://CDS.VizieR/J/ApJ/890/150
Title:
X-ray binaries in M101 with HST optical data
Short Name:
J/ApJ/890/150
Date:
17 Jan 2022 00:32:05
Publisher:
CDS
Description:
The high-energy emission from nearby, star-forming galaxies is dominated by X-ray binaries, where a neutron star or black hole is accreting mass from either a low-mass (<~M_{sun}_) or high-mass (>~8M_{sun}_) star. Donor stars with intermediate masses ~3-7M_{sun}_ are also possible, but rarer in our Galaxy. Since it is not possible to separate low-, intermediate-, and high-mass X-ray binaries (LMXBs, IMXBs, and HMXBs) from their X-ray properties alone, we use optical images of M101 taken with the Hubble Space Telescope to directly constrain the masses of donor stars in X-ray binaries down to ~3M_{sun}_. For X-ray binaries that still live within their parent star cluster, the age of the cluster provides strong constraints on the mass of the donor and hence type of binary. We present the classification, on a source-by-source basis, of 140 X-ray point sources in the nearby spiral galaxy M101 (D=6.4+/-0.2Mpc). We find that, overall, HMXBs appear to follow the spiral arms, while LMXBs dominate the bulge region as expected, but also appear to form an inter-arm disk population. The X-ray luminosity functions for HMXBs and LMXBs are well fit by a power-law distribution, dN/dL_X_{propto}L^{alpha}^, with {alpha}=-1.71+/-0.06 (HMXBs) and {alpha}=-1.96+/-0.08 (LMXBs), and the brightest sources are consistent with the expectations from sampling statistics without requiring a physical cutoff. Overall, our results for HMXB and LMXB populations agree well with the specific star formation rate map presented for M101 recently by Lehmer and collaborators.
17687. X-ray binaries in NGC 1291 with Chandra
ID:
ivo://CDS.VizieR/J/ApJ/749/130
Title:
X-ray binaries in NGC 1291 with Chandra
Short Name:
J/ApJ/749/130
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Chandra studies of the X-ray binary (XRB) populations in the bulge and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources in the galaxy, 75 in the bulge and 71 in the ring, utilizing the four available Chandra observations totaling an effective exposure of 179 ks. We report photometric properties of these sources in a point-source catalog. There are {approx}40% of the bulge sources and {approx}25% of the ring sources showing >3{sigma} long-term variability in their X-ray count rate. The X-ray colors suggest that a significant fraction of the bulge ({approx}75%) and ring ({approx}65%) sources are likely low-mass X-ray binaries (LMXBs). The spectra of the nuclear source indicate that it is a low-luminosity active galactic nucleus (AGN) with moderate obscuration; spectral variability is observed between individual observations. We construct 0.3-8.0 keV X-ray luminosity functions (XLFs) for the bulge and ring XRB populations, taking into account the detection incompleteness and background AGN contamination. We reach 90% completeness limits of {approx}1.5x10^37^ and {approx}2.2x10^37^ erg/s for the bulge and ring populations, respectively. Both XLFs can be fit with a broken power-law model, and the shapes are consistent with those expected for populations dominated by LMXBs. We perform detailed population synthesis modeling of the XRB populations in NGC 1291, which suggests that the observed combined XLF is dominated by an old LMXB population. We compare the bulge and ring XRB populations, and argue that the ring XRBs are associated with a younger stellar population than the bulge sources, based on the relative overdensity of X-ray sources in the ring, the generally harder X-ray color of the ring sources, the overabundance of luminous sources in the combined XLF, and the flatter shape of the ring XLF.
17688. X-ray binaries observed in M31 with Chandra
ID:
ivo://CDS.VizieR/J/ApJ/780/83
Title:
X-ray binaries observed in M31 with Chandra
Short Name:
J/ApJ/780/83
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have created 0.3-10keV, 13yr, unabsorbed luminosity light curves for 528 X-ray sources in the central 20' of M31. We have 174 Chandra observations spaced at ~1 month intervals due to our transient monitoring program, deeper observations of the M31 nucleus, and some public data from other surveys. We created 0.5-4.5keV structure functions (SFs) for each source for comparison with the ensemble SF of active galactic nuclei (AGN). We find 220 X-ray sources with luminosities >~10^35^erg/s that have SFs with significantly more variability than the ensemble AGN SF, and which are likely X-ray binaries (XBs). A further 30 X-ray sources were identified as XBs using other methods. We therefore have 250 probable XBs in total, including ~200 new identifications. This result represents great progress over the ~50 XBs and ~40 XB candidates previously identified out of the ~2000 X-ray sources within the D_25_ region of M31; it also demonstrates the power of SF analysis for identifying XBs in external galaxies. We also identify a new transient black hole candidate, associated with the M31 globular cluster B128.
17689. X-ray bright AGN in massive galaxy clusters
ID:
ivo://CDS.VizieR/J/MNRAS/446/2709
Title:
X-ray bright AGN in massive galaxy clusters
Short Name:
J/MNRAS/446/2709
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a new analysis of the X-ray selected active galactic nuclei (AGN) population residing in and behind 135 of the most massive galaxy clusters in the redshift range of 0.2<z<0.9 observed with Chandra. With a sample of more than 11000 X-ray point sources, we are able to measure, for the first time, evidence for evolution in the cluster AGN population beyond the expected evolution of field AGN. Our analysis shows that overall number density of cluster AGN scales with the cluster mass as ~M_500_-1.2. There is no evidence for the overall number density of cluster member X-ray AGN depending on the cluster redshift in a manner different than field AGN, nor is there any evidence that the spatial distribution of cluster AGN (given in units of the cluster overdensity radius r_500_) strongly depends on the cluster mass or redshift. The M^-1.2+/-0.7^ scaling relation we measure is consistent with theoretical predictions of the galaxy merger rate in clusters, which is expected to scale with the cluster velocity dispersion, {sigma}, as ~{sigma}^-3^ or ~M^-1^. This consistency suggests that galaxy mergers may be an important contributor to the cluster AGN population, a result that is further corroborated by visual inspection of Hubble images for 23 spectroscopically confirmed cluster member AGN in our sample. A merger-driven scenario for the triggering of X-ray AGN is not strongly favoured by studies of field galaxies, however, suggesting that different mechanisms may be primarily responsible for the triggering of cluster and field X-ray AGN.
17690. X-ray-bright optically faint AGN
ID:
ivo://CDS.VizieR/J/PASJ/70/S36
Title:
X-ray-bright optically faint AGN
Short Name:
J/PASJ/70/S36
Date:
21 Oct 2021
Publisher:
CDS
Description:
We construct a sample of X-ray-bright optically faint active galactic nuclei by combining Subaru Hyper Suprime-Cam, XMM-Newton, and infrared source catalogs. Fifty-three X-ray sources satisfying i-band magnitude fainter than 23.5mag and X-ray counts with the EPIC-PN detector larger than 70 are selected from 9.1 deg^2^, and their spectral energy distributions (SEDs) and X-ray spectra are analyzed. Forty-four objects with an X-ray to i-band flux ratio FX/Fi>10 are classified as extreme X-ray-to-optical flux sources. Spectral energy distributions of 48 among 53 are represented by templates of type 2 AGNs or star-forming galaxies and show the optical signature of stellar emission from host galaxies in the source rest frame. Infrared/optical SEDs indicate a significant contribution of emission from dust to the infrared fluxes, and that the central AGN is dust obscured. The photometric redshifts determined from the SEDs are in the range of 0.6-2.5. The X-ray spectra are fitted by an absorbed power-law model, and the intrinsic absorption column densities are modest (best-fit logNH=20.5-23.5cm^-2^ in most cases). The absorption-corrected X-ray luminosities are in the range of 6x10^42^-2x10^45^erg/s. Twenty objects are classified as type 2 quasars based on X-ray luminosity and NH. The optical faintness is explained by a combination of redshifts (mostly z>1.0), strong dust extinction, and in part a large ratio of dust/gas.

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