Identification of X-ray sources< 1◦ from Seyfert galaxies

نویسنده

  • H. Arp
چکیده

Excess numbers of X-ray sources around bright Seyfert galaxies have been demonstrated with significances of association up to 7.4 sigma (Radecke, preceding paper). The optical identification of these sources is shown here to be predominantly blue stellar objects (BSO’s) of which some are already catalogued as quasars. Excluding the two brightest Seyferts, a subset of 24 with apparent magnitudes between 8.04 ≤ B T ≤ 12.90mag. show a minimum excess of > 46 bright X-ray sources. These excess X-ray sources are generally distributed between 10′ < r < 40′ and 12 of the Seyferts show conspicuous pairs of X-ray sources across their active nuclei. Additional pairing and alignment of sources is seen for the remaining Seyferts. Among the paired X-ray sources, 53 have been identified as BSO’s. Somedouble andmultipleBSO’s have been identifiedwhich are candidates for groups and associations of quasars. Some groups are well aligned and some centered on small blue galaxies. Four previously known BL Lac objects fall close enough to the Seyferts in this sample to confirm, at a significance level of 1 − 2 × 10−9, a previously reported association of BL Lac objects with bright, low redshift galaxies.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies

We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X...

متن کامل

The contribution of Narrow - Line Seyfert 1 galaxies to the soft X - ray background

The ROSAT Ultradeep HRI survey in the Lockman Hole contains a complete sample of 91 X-ray sources with fluxes in the 0.5-2 keV band larger than 1.2 · 10 −15 erg cm −2 s −1 , where over 75 % of the sources are quasars or Seyfert galaxies. During the course of our optical identification work, we have obtained optical spectra of 67 narrow emission line galaxies (NELG), which are physically not ass...

متن کامل

The response of the X - ray luminosity to the interaction strength in Seyfert 1 & 2 galaxies

We have correlated a sample of 99 Seyfert 1 & 98 Seyfert 2 (Rafanelli et al., 1995) interacting galaxies with the survey and pointed ROSAT data and have detected 91 Seyferts 1 & 47 Seyfert 2s in the X-ray band. We have performed spectral and timing analysis of the X-ray detected sources, and we have examined the relation of the X-ray luminosity L X with the interaction strength Q.

متن کامل

Identification of soft high galactic latitude RASS X-ray sources

We present a summary of spectroscopic identifications of bright soft high galactic latitude X-ray sources from the ROSAT All-Sky Survey with total PSPC count rates 0.11 < CR < 0.5 cts s−1 and hardness ratios HR1 < 0. This study supplements the identification program of a complete sample of sources withCR ≥ 0.5 cts s−1 presented previously. Spectroscopic identifications are presented for 70 of 7...

متن کامل

The ROSAT Bright Survey: I. Identification of an AGN sample with hard ROSAT X-ray spectra

The ROSAT Bright Survey (RBS) aims to completely optically identify the more than 2000 brightest sources detected in the ROSAT all-sky survey at galactic latitudes |b| > 30◦ (excluding LMC, SMC, Virgo cluster). This paper presents a subsample of 66 bright point-like ROSAT survey sources with almost hard PSPC spectra, the hardness ratio HR1 is > 0.5 for most of the sources. The subsample could b...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1996