- ID:
- ivo://CDS.VizieR/J/A+A/539/A48
- Title:
- XMM AGN optical-UV luminosities
- Short Name:
- J/A+A/539/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Active galactic nuclei (AGN) emit radiation over a wide range of wavelengths, with a peak of emission in the far-UV region of the electromagnetic spectrum, a spectral region that is historically difficult to observe. Using optical, GALEX UV, and XMM-Newton data we derive the spectral energy distribution (SED) from the optical/UV to X-ray regime of a sizeable sample of AGN. The principal motivation is to investigate the relationship between the optical/UV emission and the X-ray emission and provide bolometric corrections to the hard X-ray (2-10keV) energy range, k_bol_, the latter being a fundamental parameter in current physical cosmology.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/1422
- Title:
- 2XMM AGN X-ray and mid-IR luminosities
- Short Name:
- J/MNRAS/449/1422
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined the relation between the AGN luminosities at rest-frame 6{mu}m associated with the dusty torus emission and at 2-10keV energies using a complete, X-ray-flux-limited sample of 232 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The objects have intrinsic X-ray luminosities between 10^42^ and 10^46^erg/s and redshifts from 0.05 to 2.8. The rest-frame 6{mu}m luminosities were computed using data from the Wide-field Infrared Survey Explorer and are based on a spectral energy distribution decomposition into AGN and galaxy emission. The best-fitting relationship for the full sample is consistent with being linear, L_6{mu}m_{prop.to}L_2-10keV_^0.99+/-0.03^, with intrinsic scatter, {Delta}logL_6{mu}m_~0.35dex. The L_6{mu}m_/L_2-10keV_ luminosity ratio is largely independent of the line-of-sight X-ray absorption. Assuming a constant X-ray bolometric correction, the fraction of AGN bolometric luminosity reprocessed in the mid-IR decreases weakly, if at all, with the AGN luminosity, a finding at odds with simple receding torus models. Type 2 AGN have redder mid-IR continua at rest-frame wavelengths <12{mu}m and are overall ~1.3-2 times fainter at 6{mu}m than type 1 AGN at a given X-ray luminosity. Regardless of whether type 1 and type 2 AGN have the same or different nuclear dusty toroidal structures, our results imply that the AGN emission at rest-frame 6{mu}m is not isotropic due to self-absorption in the dusty torus, as predicted by AGN torus models. Thus, AGN surveys at rest-frame ~6{mu}m are subject to modest dust obscuration biases.
- ID:
- ivo://CDS.VizieR/J/ApJ/641/410
- Title:
- XMM and Chandra X-ray sources near 4U 1755-33
- Short Name:
- J/ApJ/641/410
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on new X-ray observations of the large-scale jets recently discovered in X-rays from the black hole candidate 4U 1755-33. Our observations in 2004 show that the jets found in 2001 are still present in X-rays. However, sensitive radio observations in 2004 failed to detect the jets.
- ID:
- ivo://CDS.VizieR/J/A+A/459/693
- Title:
- XMM/CDFS AGN intrinsic absorption
- Short Name:
- J/A+A/459/693
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine bright XMM-Newton data with the Chandra Deep Field South observations to explore the behavior of the intrinsic AGN absorption, as a function of redshift and luminosity. Our sample consists of 359 sources selected in the hard 2-8keV band, spanning the flux range 6x10^-16^-3x10^-13^erg/cm^2^/s with a high rate of spectroscopic or photometric redshift completeness (100 and 85 per cent respectively for the Chandra and XMM-Newton data). We derive the column density values using X-ray spectral fits. We find that the fraction of obscured AGN falls with increasing luminosity in agreement with previous findings. The fraction of obscured AGN shows an apparent increase at high redshifts (z>2). Simulations show that this effect can most probably be attributed to the fact that at high redshifts the column densities are overestimated.
21555. XMM/CFDS catalogue
- ID:
- ivo://CDS.VizieR/J/MNRAS/350/785
- Title:
- XMM/CFDS catalogue
- Short Name:
- J/MNRAS/350/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the X-ray source catalogues for the XMM surveys of the 3-h and 14-h (also known as the Groth Strip) Canada-France Redshift Survey fields (0.5-10keV flux range ~2x10^-15^-10^-13^erg/cm^2^/s). We use a subset of the XMM sources, which have Chandra positions, to determine the best method of obtaining optical identifications of sources with only XMM positions. We find optical identifications for 79 per cent of the XMM sources for which there are deep optical images. The sources without optical identifications are likely to be optically fainter and have higher redshifts than the sources with identifications. We have estimated 'photometric redshifts' for the identified sources, calibrating our method using ~200 galaxies in the fields with spectroscopic redshifts. We find that the redshift distribution has a strong peak at z~0.7.
21556. XMM/Chandra study of IC 10
- ID:
- ivo://CDS.VizieR/J/MNRAS/362/1065
- Title:
- XMM/Chandra study of IC 10
- Short Name:
- J/MNRAS/362/1065
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an X-ray study of our nearest starburst galaxy IC 10, based on XMM-Newton and Chandra observations. A list of 73 XMM-Newton and 28 Chandra detections of point-like X-ray sources in the field is provided; a substantial fraction of them are likely stellar objects in the Milky Way due to the low Galactic latitude location of IC 10.
- ID:
- ivo://CDS.VizieR/J/ApJS/172/182
- Title:
- XMM Clusters of galaxies in COSMOS field
- Short Name:
- J/ApJS/172/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for galaxy clusters in the first 36 XMM-Newton pointings on the Cosmic Evolution Survey (COSMOS) field. We reach a depth for a total cluster flux in the 0.5-2keV band of 3x10^-15^ergs/cm^2^/s, having one of the widest XMM-Newton contiguous raster surveys, covering an area of 2.1deg^2^. Cluster candidates are identified through a wavelet detection of extended X-ray emission. Verification of the cluster candidates is done based on a galaxy concentration analysis in redshift slices of thickness 0.1-0.2 in redshift, using the multiband photometric catalog of the COSMOS field and restricting the search to z<1.3 and i_AB_<25. We identify 72 clusters and derive their properties based on the X-ray cluster scaling relations. A statistical description of the survey in terms of the cumulative log(N>S)-logS distribution compares well with previous results, although yielding a somewhat higher number of clusters at similar fluxes. The X-ray luminosity function of COSMOS clusters matches well the results of nearby surveys, providing a comparably tight constraint on the faint-end slope of alpha=1.93+/-0.04. For the probed luminosity range of (8x10^42^)-(2x10^44^)ergs/s, our survey is in agreement with and adds significantly to the existing data on the cluster luminosity function at high redshifts and implies no substantial evolution at these luminosities to z=1.3.
21558. XMM-COSMOS Type 1 AGNs
- ID:
- ivo://CDS.VizieR/J/A+A/512/A34
- Title:
- XMM-COSMOS Type 1 AGNs
- Short Name:
- J/A+A/512/A34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the X-ray to optical properties of a sample of 545 X-ray selected Type 1 AGN, from the XMM-COSMOS survey, over a wide range of redshifts (0.04<z<4.25) and X-ray luminosities (40.6<=LogL[2-10]keV<=45.3). About 60% of them are spectroscopically identified Type 1 AGN, while the others have a reliable photometric redshift and are classified as Type 1 AGN on the basis of their multi-band Spectral Energy Distributions. We discuss the relationship between UV and X-ray luminosity, as parameterized by the alpha_ox_ spectral slope, and its dependence on redshift and luminosity.
- ID:
- ivo://CDS.VizieR/J/A+A/445/155
- Title:
- XMM count-rates in M 55 and NGC 3201
- Short Name:
- J/A+A/445/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed two low concentration Galactic globular clusters with the X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction of M 55 and 62 in the field of view of NGC 3201. Using the statistical LogN-LogS relationship of extragalactic sources derived from XMM-Newton Lockman Hole observations, to estimate the background source population, we estimate that very few of the sources (1.5+/-1.0) in the field of view of M 55 actually belong to the cluster. These sources are located in the centre of the cluster as we expect if the cluster has undergone mass segregation. NGC 3201 has approximately 15 related sources, which are centrally located but are not constrained to lie within the half mass radius. The sources belonging to this cluster can lie up to 5 core radii from the centre of the cluster which could imply that this cluster has been perturbed. Using X-ray (and optical, in the case of M 55 ) colours, spectral and timing analysis (where possible) and comparing these observations to previous X-ray observations, we find evidence for sources in each cluster that could be cataclysmic variables, active binaries, millisecond pulsars and possible evidence for a quiescent low mass X-ray binary with a neutron star primary, even though we do not expect any such objects in either of the clusters, due to their low central concentrations. The majority of the other sources are background sources, such as AGN.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A188
- Title:
- 4XMM-DR9-HECATE-based ULX catalogue
- Short Name:
- J/A+A/659/A188
- Date:
- 25 Mar 2022 09:09:32
- Publisher:
- CDS
- Description:
- Ultraluminous X-ray sources (LX>1x10^39^erg/s, ULXs) are excellent probes for extreme accretion physics, star formation history in galaxies, and intermediate-mass black holes searches. As the sample size of X-ray data from modern observatories such as XMM-Newton and Chandra increases, producing extensive catalogues of ULXs and studying their collective properties has become both a possibility and a priority. Our aim is to build a clean updated ULX catalogue based on one of the most recent XMM-Newton X-ray serendipitous survey data releases, 4XMM-DR9, and the most recent and exhaustive catalogue of nearby galaxies, HECATE. We performed a preliminary population study to test if the properties of the expanded XMM-Newton ULX population are consistent with previous findings. We performed positional cross-matches between XMM-Newton sources and HECATE objects to identify host galaxies, and we used distance and luminosity arguments to identify ULX candidates. We flagged interlopers by finding known counterparts in external catalogues and databases such as Gaia DR2 SSDS, Pan-STARRS1, the NASA/IPAC Extragalactic Database, and SIMBAD. Source, galaxy and variability parameters from 4XMM-DR9, HECATE, and 4XMM-DR9s were used to study the spectral, abundances and variability properties of the ULX sample. We identify 779 ULX candidates, 94 of which hold LX>5x10^40^erg/s. Spiral galaxies are more likely to host ULXs. For early spiral galaxies the number of ULX candidates per star-forming rate is consistent with previous studies, while a significant ULX population in elliptical and lenticular galaxies also exists. Candidates hosted by late-type galaxies tend to present harder spectra and to undergo more extreme inter-observation variability than those hosted by early-type galaxies. Approximately 30 candidates with LX>1x10^41^erg/s are also identified, constituting the most interesting candidates for intermediate-mass black hole searches. We have built the largest ULX catalogue to date. Our results on the spectral and abundance properties of ULXs confirm the findings made by previous studies based on XMM-Newton and Chandra data, while our population-scale study on variability properties is unprecedented. Our study, however, provides limited insight into the properties of the brightest ULX candidates due to the small sample size. The expected growth of X-ray catalogues and potential future follow-ups will aid in drawing a clearer picture.
