Search

Start Over Capability Type Simple Cone Search
2711. Chandra X-ray point sources in Cen A
ID:
ivo://CDS.VizieR/J/ApJ/560/675
Title:
Chandra X-ray point sources in Cen A
Short Name:
J/ApJ/560/675
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from two Chandra X-ray Observatory observations of the X-ray point source population in the nearby radio galaxy Centaurus A (NGC 5128). Using a wavelet decomposition detection algorithm, we detect 246 individual point sources above a limiting luminosity of ~2*10^36^ergs/s, 82 of which are detected in both data sets where the fields of view overlap. Thirty-eight sources were detected in only one observation but were within the field of view of both pointings, implying considerable variability. We identify eight foreground stars in our observations. We also identify nine of the sources with known globular clusters in Centaurus A. All previously observed ROSAT sources within our field of view are detected.
2712. CHANDRA X-ray point sources in Cen A (NGC 5128)
ID:
ivo://CDS.VizieR/J/A+A/447/71
Title:
CHANDRA X-ray point sources in Cen A (NGC 5128)
Short Name:
J/A+A/447/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have studied the X-ray point source population of Centaurus A (NGC 5128) using data from four archival CHANDRA observations. We detected 272 point-like X-ray sources within a radius of 10' from the centre. Approximately half of these are CXB sources, with the remaining half being LMXBs. The spatial distribution of the LMXBs, both azimuthally averaged and 2D, is consistent with the distribution of the K-band light observed in the 2MASS survey. After correction for the incompleteness effect we constrain the LMXB luminosity function down to ~2x10^36^erg/s, much lower than previous studies of LMXBs in elliptical galaxies.
2713. Chandra X-ray point sources in nearby galaxies
ID:
ivo://CDS.VizieR/J/ApJ/602/231
Title:
Chandra X-ray point sources in nearby galaxies
Short Name:
J/ApJ/602/231
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have analyzed Chandra ACIS observations of 32 nearby spiral and elliptical galaxies and present the results of 1441 X-ray point sources that were detected in these galaxies. The total point-source X-ray (0.3-8.0keV) luminosity L_XP_ is well correlated with the B-band, K-band, and FIR+UV luminosities of spiral host galaxies and is well correlated with the B-band and K-band luminosities of elliptical galaxies. This suggests an intimate connection between L_XP_ and both the old and young stellar populations, for which K and FIR+UV luminosities are reasonable proxies for the galaxy mass M and star formation rate SFR.
2714. Chandra X-ray point sources in the Fornax cluster
ID:
ivo://CDS.VizieR/J/ApJ/876/53
Title:
Chandra X-ray point sources in the Fornax cluster
Short Name:
J/ApJ/876/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on archival Chandra observations with a total exposure of 1.3Ms, we study X-ray point sources in the Fornax cluster of galaxies, with the primary aim of searching for intracluster X-ray source populations. We detect 1177 point sources out to a projected radius of ~30' (~180kpc) from the cluster center and down to a limiting 0.5-8keV luminosity of ~3x10^37^erg/s. We construct the source surface density profile, after excluding sources associated with foreground stars, known globular clusters, ultra-compact dwarfs, and galactic nuclei. From this profile we statistically identify ~183 excess sources that are not associated with the bulk stellar content of the individual member galaxies of Fornax, nor with the cosmic X-ray background. Taking into account Poisson error and cosmic variance, the cumulative significance of this excess is at the >~2{sigma} level (with a maximum of 3.6{sigma}) outside three effective radii of the central giant elliptical, NGC 1399. The luminosity function of the excess sources is found to be significantly steeper than that of the GC-hosting sources (presumably low-mass X-ray binaries (LMXBs)), disfavoring the possibility that unidentified GCs are primarily responsible for the excess. We show that a large fraction of the excess can be related to the extended stellar halo of NGC 1399 and/or the diffuse intracluster light, thus providing strong evidence for the presence of intracluster X-ray sources in Fornax, the second unambiguous case for a galaxy cluster after Virgo. Other possible origins of the excess, including supernova-kicked LMXBs and stripped nucleated dwarf galaxies are discussed.
2715. Chandra X-ray point sources of NGC 300
ID:
ivo://CDS.VizieR/J/ApJ/758/15
Title:
Chandra X-ray point sources of NGC 300
Short Name:
J/ApJ/758/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the source catalog of a new Chandra ACIS-I observation of NGC 300 obtained as part of the Chandra Local Volume Survey. Our 63ks exposure covers ~88% of the D_25_ isophote (R{approx}6.3kpc) and yields a catalog of 95 X-ray point sources detected at high significance to a limiting unabsorbed 0.35-8 keV luminosity of ~10^36^erg/s. Sources were cross-correlated with a previous XMM-Newton catalog, and we find 75 "X-ray transient candidate" sources that were detected by one observatory, but not the other. We derive an X-ray scale length of 1.7+/-0.2kpc and a recent star formation rate of 0.12M_{sun}_/yr in excellent agreement with optical observations. Deep, multi-color imaging from the Hubble Space Telescope, covering ~32% of our Chandra field, was used to search for optical counterparts to the X-ray sources, and we have developed a new source classification scheme to determine which sources are likely X-ray binaries, supernova remnants, and background active galactic nucleus candidates. Finally, we present the X-ray luminosity functions (XLFs) at different X-ray energies, and we find the total NGC 300 X-ray point-source population to be consistent with other late-type galaxies hosting young stellar populations (<~50Myr). We find that XLF of sources associated with older stellar populations has a steeper slope than the XLF of X-ray sources coinciding with young stellar populations, consistent with theoretical predictions.
2716. Chandra X-ray sources and NIR identifications
ID:
ivo://CDS.VizieR/J/ApJ/635/214
Title:
Chandra X-ray sources and NIR identifications
Short Name:
J/ApJ/635/214
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b)~(28.5{deg}, 0.0{deg}), where no discrete X-ray source had been reported previously. We have detected 274 new point X-ray sources (4{sigma} confidence), as well as strong Galactic diffuse emission within two partially overlapping ACIS-I fields (~250arcmin^2^ in total). The point-source sensitivity was 3x10^-15^ergs/s/cm^2^ in the hard X-ray band (2-10keV) and 2x10^-16^ergs/s/cm^2^ in the soft band (0.5-2keV). The sum of all the detected point-source fluxes accounts for only 10% of the total X-ray flux in the field of view. Following up the Chandra observation, we have performed a near-infrared (NIR) survey with SofI at ESO/NTT. Almost all the soft X-ray sources have been identified in the NIR, and their spectral types are consistent with main-sequence stars, suggesting that most of them are nearby X-ray-active stars.
2717. Chandra X-ray sources in LALA Cetus field
ID:
ivo://CDS.VizieR/J/ApJ/669/765
Title:
Chandra X-ray sources in LALA Cetus field
Short Name:
J/ApJ/669/765
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 174ks Chandra Advanced CCD Imaging Spectrometer exposure of the Large Area Lyman Alpha Survey (LALA) Cetus field is the second of the two deep Chandra images on LALA fields. In this paper we present the Chandra X-ray sources detected in the Cetus field, along with an analysis of X-ray source counts, stacked X-ray spectrum, and optical identifications. A total of 188 X-ray sources were detected: 174 in the 0.5-7.0keV band, 154 in the 0.5-2.0keV band, and 113 in the 2.0-7.0keV band. The X-ray source counts were derived and compared with LALA field (172ks exposure).
2718. Chandra X-ray sources in M101
ID:
ivo://CDS.VizieR/J/ApJ/561/189
Title:
Chandra X-ray sources in M101
Short Name:
J/ApJ/561/189
Date:
21 Oct 2021
Publisher:
CDS
Description:
A deep (98.2ks) 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 data set we have created a catalog of the 110 sources from the S3 chip detected with a significance of greater than 3{sigma}. This detection threshold corresponds to a flux of ~10^-16^ergs/cm^2^/s and a luminosity of ~10^36^ergs/s for a distance to M101 of 7.2Mpc. The sources display a distinct correlation with the spiral arms of M101 and include a variety of X-ray binaries, supersoft sources, supernova remnants, and other objects of which only ~27 are likely to be background sources.
2719. Chandra X-ray sources in M30 (NGC 7099)
ID:
ivo://CDS.VizieR/J/ApJ/657/286
Title:
Chandra X-ray sources in M30 (NGC 7099)
Short Name:
J/ApJ/657/286
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the detection of six discrete, low-luminosity (LX<10^33^erg/s) X-ray sources, located within 12" of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within the half-mass radius, from a 50ks Chandra ACIS-S exposure.
2720. Chandra X-ray sources in NGC 3556
ID:
ivo://CDS.VizieR/J/ApJ/598/969
Title:
Chandra X-ray sources in NGC 3556
Short Name:
J/ApJ/598/969
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a 60ks Chandra ACIS-S observation of the isolated edge-on spiral galaxy NGC 3556, together with a multiwavelength analysis of various discrete X-ray sources and diffuse X-ray features.

Limit your search

more »

more »

more »

more »

more »

more »