- ID:
- ivo://CDS.VizieR/J/MNRAS/360/782
- Title:
- X-ray-selected normal galaxies
- Short Name:
- J/MNRAS/360/782
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we estimate the local (z<0.22) X-ray luminosity function of 'normal' galaxies derived from the XMM-Newton Needles in the Haystack Survey. This is an on-going project that aims to identify X-ray-selected normal galaxies (i.e. non-AGN dominated) in the local Universe. We are using a total of 70 XMM-Newton fields covering an area of 11deg^2^ which overlap with the Sloan Digital Sky Survey Data Release 2. Normal galaxies are selected on the basis of their resolved optical light profile, their low X-ray-to-optical flux ratio [log(fx/fo)<-2] and soft X-ray colours. We find a total of 28 candidate normal galaxies to the 0.58keV band flux limit of 2x10^-15^erg/cm2/s. Optical spectra are available for most sources in our sample (82 per cent). These provide additional evidence that our sources are bona fide normal galaxies with X-ray emission coming from diffuse hot gas emission and/or X-ray binaries rather than a supermassive black hole.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/797/91
- Title:
- X-Ray source properties for NGC 2207/IC 2163
- Short Name:
- J/ApJ/797/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive study of the total X-ray emission from the colliding galaxy pair NGC 2207/IC 2163, based on Chandra, Spitzer, and GALEX data. We detect 28 ultraluminous X-ray sources (ULXs), 7 of which were not detected previously because of X-ray variability. Twelve sources show significant long-term variability, with no correlated spectral changes. Seven sources are transient candidates. One ULX coincides with an extremely blue star cluster (B-V=-0.7). We confirm that the global relation between the number and luminosity of ULXs and the integrated star-formation rate (SFR) of the host galaxy also holds on local scales. We investigate the effects of dust extinction and age on the X-ray binary (XRB) population on subgalactic scales. The distributions of N_X_ and L_X_ are peaked at L_IR_/L_NUV_~1, which may be associated with an age of ~10 Myr for the underlying stellar population. We find that approximately one-third of the XRBs are located in close proximity to young star complexes. The luminosity function of the XRBs is consistent with that typical for high-mass XRBs and appears unaffected by variability. We disentangle and compare the X-ray diffuse spectrum with that of the bright XRBs. The hot interstellar medium dominates the diffuse X-ray emission at E<~1 keV and has a temperature kT=0.28_-0.04_^+0.05^ keV and intrinsic 0.5-2 keV luminosity of 7.9x10^40^ erg/s, a factor of ~2.3 higher than the average thermal luminosity produced per unit SFR in local star-forming galaxies. The total X-ray output of NGC 2207/IC 2163 is 1.5x10^41^ erg/s, and the corresponding total integrated SFR is 23.7 M_{sun}_/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/319/18
- Title:
- X-ray sources <1 degree from Seyfert galaxies
- Short Name:
- J/A+A/319/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Archived PSPC observations of 26 Seyfert galaxies have been analyzed for bright X-ray sources out to the full extent of the field (< about 50'). Of all Seyferts known this represents a sample 88% complete to B_T_=10mag, 74% complete to 11mag and 50% complete to 12mag. Using the same reduction algorithm, 14 fields centered on stars at high galactic latitudes have been used as control fields. Excluding the two brightest Seyferts, a subset of 24 Seyferts with corrected apparent magnitude between 8.04<B^o,i^_T_<12.90mag show a minimum excess of 46 bright X-ray sources generally distributed between 10 and 25' from the target galaxy. The significances of association of these sources with the Seyferts in the median brightness range are as high as 7.4-sigma.
- ID:
- ivo://CDS.VizieR/J/AJ/133/220
- Title:
- X-ray sources in galaxy pairs
- Short Name:
- J/AJ/133/220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive study of the local environments of four elliptical+spiral (E+S) galaxy pairs with the main goal of investigating their formation/evolution histories. We obtained new XMM-Newton data for two pairs (RR 143 and RR 242) that complement existing ROSAT data for the other two (RR 210 and RR 216).
- ID:
- ivo://CDS.VizieR/J/ApJ/706/693
- Title:
- X-ray sources in NGC 5866
- Short Name:
- J/ApJ/706/693
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- S0 galaxies are often thought to be passively evolved from spirals after star formation is quenched. To explore what is actually occurring in such galaxies, we present a multi-wavelength case study of NGC 5866 - a nearby edge-on S0 galaxy in a relatively isolated environment. This study shows strong evidence for dynamic activities in the interstellar medium, which are most likely driven by supernova explosions in the galactic disk and bulge. Understanding these activities can have strong implications for studying the evolution of such galaxies. We utilize Chandra, Hubble Space Telescope, and Spitzer data as well as ground-based observations to characterize the content, structure, and physical state of the medium and its interplay with the stellar component in NGC 5866. We reveal the presence of diffuse X-ray-emitting hot gas, which extends as far as 3.5kpc away from the galactic plane and can be heated easily by Type Ia SNe in the bulge.
- ID:
- ivo://CDS.VizieR/J/ApJ/682/1020
- Title:
- X-ray sources in NGC 4194 and NGC 7541
- Short Name:
- J/ApJ/682/1020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the X-ray point-source population and 2-10keV luminosity for two galaxies with high star formation rates (SFRs), NGC 4194 and NGC 7541 and combined our results with a sample of galaxies with SFRs above 1M_{sun}_/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/459/777
- Title:
- X-ray sources in Sagittarius and Carina dSph
- Short Name:
- J/A+A/459/777
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- ROSAT observations found no convincing evidence for X-ray sources located in local dwarf spheroidal galaxies (dSph). Now with more sensitive instruments on board Chandra and XMM-Newton we can reach fainter luminosity levels. We report on an observation of the Sagittarius (Sgr) dSph made using Chandra and an observation of the Carina (Car) dSph made using XMM-Newton. Our observations are sensitive to sources with X-ray luminosities in the 0.1-10keV band of ~1x10^32^erg/s and 3x10^34^erg/s for the Sgr and Car fields respectively. We have identified a total of 80 sources in the Sgr field and 53 sources in the Car field. Although the source numbers are roughly consistent with the expected number of background AGN, we found a small fraction of X-ray sources which were soft and could be located in the host dSph. Follow-up optical/IR observations may help to identify their optical counterparts and hence determine their nature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/911
- Title:
- X-ray sources in the AKARI NEP deep field
- Short Name:
- J/MNRAS/446/911
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present data products from the 300ks Chandra survey in the AKARI North Ecliptic Pole (NEP) deep field. This field has a unique set of 9-band infrared photometry covering 2-24 micron from the AKARI Infrared Camera, including mid-infrared (MIR) bands not covered by Spitzer. The survey is one of the deepest ever achieved at ~15 micron, and is by far the widest among those with similar depths in the MIR. This makes this field unique for the MIR-selection of AGN at z~1. We design a source detection procedure, which performs joint Maximum Likelihood PSF fits on all of our 15 mosaicked Chandra pointings covering an area of 0.34 square degree. The procedure has been highly optimized and tested by simulations. We provide a point source catalog with photometry and Bayesian-based 90 per cent confidence upper limits in the 0.5-7, 0.5-2, 2-7, 2-4, and 4-7keV bands. The catalog contains 457 X-ray sources and the spurious fraction is estimated to be ~1.7 per cent. Sensitivity and 90 per cent confidence upper flux limits maps in all bands are provided as well. We search for optical MIR counterparts in the central 0.25 square degree, where deep Subaru Suprime-Cam multiband images exist. Among the 377 X-ray sources detected there, ~80 per cent have optical counterparts and ~60 per cent also have AKARI mid-IR counterparts. We cross-match our X-ray sources with MIR-selected AGN from Hanami et al. Around 30 per cent of all AGN that have MID-IR SEDs purely explainable by AGN activity are strong Compton-thick AGN candidates.
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/2302
- Title:
- X-ray sources in the Phoenix dwarf galaxy
- Short Name:
- J/MNRAS/422/2302
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the first X-ray images of the Phoenix dwarf galaxy, taken with XMM-Newton in 2009 July. This Local Group dwarf galaxy shares similarities with the Small Magellanic Cloud (SMC) including a burst of star formation ~50Myr ago. The SMC has an abundance of high-mass X-ray binaries (HMXBs) and so we have investigated the possibility of an HMXB population in Phoenix with the intention of furthering the understanding of the HMXB-star formation rate relation. The data from the combined European Photon Imaging Cameras (EPIC) were used to distinguish between different source classes [foreground stars, background galaxies, active galactic nuclei (AGN) and supernova remnants] using EPIC hardness ratios and correlations with optical and radio catalogues.
- ID:
- ivo://CDS.VizieR/J/ApJ/681/1464
- Title:
- X-ray sources near soft gamma repeater in M31
- Short Name:
- J/ApJ/681/1464
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- GRB 070201 was a bright, short-duration, hard-spectrum gamma-ray burst detected by the Interplanetary Network. Its error quadrilateral, which has an area of 0.124deg^2^, intersects some prominent spiral arms of the nearby M31 (Andromeda) galaxy. Given the properties of this GRB, along with the fact that LIGO data argue against a compact binary merger origin in M31, it is an excellent candidate to have been an extragalactic soft gamma-ray repeater (SGR) giant flare, with an energy of 1.4x1045ergs. However, we cannot rule out the possibility that it was a short-duration GRB in the background. Analysis of ROTSE-IIIb visible-light observations of M31, taken 10.6hr after the burst and covering 42% of the GRB error region, does not reveal any optical transient down to a limiting magnitude of 17.1. We inspected archival and proprietary XMM-Newton X-ray observations of the intersection of the GRB error region and M31, obtained about 4 weeks prior to the outburst, in order to look for periodic variable X-ray sources. No SGR or anomalous X-ray pulsar (AXP) candidates (periods in the range 1-20s) were detected. We discuss the possibility of detecting extragalactic SGRs/AXPs by identifying their periodic X-ray light curves. Our simulations suggest that the probability of detecting the periodic X-ray signal of one of the known Galactic SGRs/AXPs, if placed in M31, is about 10% using a 50ks XMM-Newton exposure, increasing to 50% for a 2Ms observation.
