Abrixas

Hasinger, G.; Trümper, J.; Staubert, R.

doi:10.1007/978-94-011-4970-9_19

Cited by 58 publications

(88 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The spectral parameters have been taken from ROSAT observations of extragalactic sources; a power law with photon index 2.3 (Hasinger et al 1991;Walter & Fink 1993) is taken using the galactic absorbing column density N H (Dickey & Lockman 1990) along the line of sight. Fluxes of nearby galaxies may be lower limit values, if the X-ray emission is extended.…”

Section: The X-ray Data Basementioning

confidence: 99%

“…The last few columns contain an indicator of the data origin, the galactic absorbing column density towards the object (Dickey & Lockman 1990), the distance between the X-ray source and the optical candidate, the X-ray flux and luminosity, as well as the reliability of the correlation. Xray fluxes and luminosities have been calculated assuming a power law with photon index 2.3 (Hasinger et al 1991;Walter & Fink 1993), the relevant galactic absorbing column density N H and, if available, the distance to the source. For some sources additional remarks are available in column comment, which contains also the membership to the suspected cluster sample (marked as cl?)…”

Section: Data Tables and Imagesmentioning

confidence: 99%

See 1 more Smart Citation

Galaxy identifications in the ROSAT All-Sky Survey

Zimmermann

Boller

Döbereiner

et al. 2001

A&A

View full text Add to dashboard Cite

Abstract. In a correlation study of the ROSAT All-Sky Survey Bright Source Catalogue (RASS-BSC) with the Catalogue of Principal Galaxies (PGC) 904 X-ray sources were found that possess possible extragalactic counterparts within a search radius of 100 arcsec. A visual screening process was applied to classify the reliability of the correlations. 547 correlations have been quoted as reliable identifications. From these, 349 sources are known as active galaxies. Although for the other sources no hints for activity were found in the literature, 69% of those for which we have distances show X-ray luminosities exceeding those of normal galaxies, a clear sign that these galaxies also own hitherto unreported X-ray active components. Some objects are located inside or in the direction of a known group or cluster of galaxies. Their X-ray flux may therefore be in part affected by hot gas emission. Luminosity and log N− log S distributions are used to characterize different subsamples. Nuclei that are both optically and X-ray active are found predominantly in spirals. Two special source samples are defined, one with candidates for X-ray emission from hitherto unknown groups or clusters of galaxies, and one with high X-ray luminosity sources, that are likely candidates to possess hitherto unreported active galactic nuclei. Besides a compilation of X-ray and optical parameters, also X-ray overlays on optical images for all the objects are supplied as part of this work.

show abstract

Section: The X-ray Data Basementioning

confidence: 99%

Section: Data Tables and Imagesmentioning

confidence: 99%

Galaxy identifications in the ROSAT All-Sky Survey

Zimmermann

Boller

Döbereiner

et al. 2001

A&A

View full text Add to dashboard Cite

show abstract

“…One of our group candidates, 1755.4+6803, lies near the EMSS cluster's position, but the VLA source lies several arcminutes east of the main cluster emission and may not be related. Burg et al (1992) analyzed a 50 ksec PSPC pointing and all-sky scans, and identified a region of extended, low X-ray surface brightness (first reported by Hasinger et al 1991) as a new cluster with a richness class of 0 and redshift ∼ 0.09. This cluster, labeled NEPX1, along with six Abell clusters and other likely groups of similar redshift within 50 Mpc, suggest a supercluster is present.…”

Section: Galaxy Groups and Clustersmentioning

confidence: 99%

Radio-loud ROSAT sources near the North Ecliptic Pole

Brinkmann

Chester

Kollgaard

et al. 1999

Astron. Astrophys. Suppl. Ser.

View full text Add to dashboard Cite

Abstract. A deep and large-area survey of the North Ecliptic Pole region was made with the ROSAT All-Sky Survey and the VLA to elucidate the population of radioloud extragalactic objects. A region of 29.3 square degrees was surveyed with sensitivities around 5 10 −14 erg scm −2 in the soft X-ray band and 1 mJy at 1.5 GHz. Optical counterparts were sought on digitized Schmidt plates from POSS-I and II. Seventy-four reliable RASS-VLA sources were found.The sample is a heterogeneous mixture of Seyfert galaxies, quasars, BL Lac objects, galaxy clusters and groups containing a radio galaxy. Optical magnitudes range from B 14 to B > 22. Three results are noteworthy: (1) the bimodality in the ratio of radio to optical emission seen in optically-and X-ray-selected AGN samples is also evident in the ROSAT-VLA objects; (2) X-ray and radio selection is an effective method for locating poor galaxy clusters and groups; and (3) a considerable population of optically faint but X-ray/radio-bright objects is present. This last group may be either distant clusters with radio galaxies or "red quasars".

show abstract

“…Boldt 1987;Hasinger et al 1991;Fabian & Barcons 1992;Mushotzky et al 2000;Giacconi et al 2002;Brandt et al 2003). Most, if not all, of the CXB emission is explained by the superposition of point sources (AGNs) distributed over the Universe (see e.g.…”

Section: Introductionmentioning

confidence: 99%

The spectrum of the cosmic X-ray background observed by RTXE/PCA

Revnivtsev

Gilfanov

Sunyaev

et al. 2003

A&A

115

118

View full text Add to dashboard Cite

Abstract.We have analyzed a large set of RXTE/PCA scanning and slewing observations performed between April 1996 and March 1999. We obtained the 3-20 keV spectrum of the cosmic X-ray background (CXB) by subtracting Earth-occulted observations from observations of the X-ray sky at high galactic latitude and far away from sources. The sky coverage is approximately ∼22.6 × 10 3 deg 2 . The PCA spectrum of CXB in 3-20 keV energy band is adequately approximated by a single power law with photon index Γ ∼ 1.4 and normalization at 1 keV ∼ 9.5 phot/s/cm 2 /keV/sr. Instrumental background uncertainty precludes accurate RXTE/PCA measurements of the spectrum of cosmic X-ray background at energies above 15 keV and therefore we cannot detect the high energy cutoff observed by the HEAO-1 A2 experiment. Deep observations of the 6 high latitude points used to model the PCA background provide a coarse measure of the spatial variation of the CXB. The CXB variations are consistent with a fixed spectral shape and variable normalization characterized by a fractional rms amplitude of ∼7% on angular scales of ∼1 square deg.

show abstract

Abrixas

Cited by 58 publications

References 3 publications

Galaxy identifications in the ROSAT All-Sky Survey

Galaxy identifications in the ROSAT All-Sky Survey

Radio-loud ROSAT sources near the North Ecliptic Pole

The spectrum of the cosmic X-ray background observed by RTXE/PCA

Contact Info

Product

Resources

About