J/A+A/319/33 Identification of X-ray sources around Seyferts (Arp 1997)
Identification of X-ray sources <1° from Seyfert galaxies.
Arp H.
<Astron. Astrophys. 319, 33 (1997)>
=1997A&A...319...33A 1997A&A...319...33A (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert ; X-ray sources
Keywords: galaxies: Seyfert; BL Lac Objects - quasars: general -
X-rays: galaxies
Abstract:
Excess numbers of X-ray sources around bright Seyfert galaxies have
been demonstrated with significances of association up to 7.4-sigma
(Radecke, 1997A&A...319...18R 1997A&A...319...18R). 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≤BTo,i≤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. Some double
and multiple BSO's have been identified which 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 1-2x10-9, a previously reported
association of BL Lac objects with bright, low redshift galaxies.
Objects:
--------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------
12 17 09.8 +07 11 29 NGC 4235
11 06 47.4 +72 34 07 NGC 3516
13 42 08.3 +35 39 15 NGC 5273
14 17 59.5 +25 08 13 NGC 5548
--------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3 85 33 Position of optically identified X-ray Sources
table3.tex 83 59 TeX version of table3
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Gal Galaxy name
9- 14 F6.1 ct/ks C Counts of the source in the .5-20keV band (1)
15 A1 --- m_C [NS] Multiplicity index no C
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 26 F4.1 s RAs Right ascension (J2000)
27 A1 --- u_RAs Uncertainty flag on right ascension
28 A1 --- DE- Declination sign
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 36 I2 arcsec DEs Declination (J2000)
37 A1 --- u_DEs Uncertainty flag on declination
38 A1 --- n_Emag [B] B when Emag is Bmag
39 A1 --- l_Emag [~] Limit flag on Emag
40- 43 F4.1 mag Emag ? E magnitude or B magnitude if n_Emag = B
45 A1 --- l_O-E Limit flag on O-E
46- 49 F4.2 mag O-E ? O-E color index
50 A1 --- n_O-E [b] b for blue
52- 58 A7 --- Ident Identification
60- 63 F4.1 arcsec DELTAx ? X optical identification position with
respect to the X-ray position (2)
65- 67 I3 arcsec DELTAy ? Y optical identification position with
respect to the X-ray position (2)
69- 85 A17 --- Rem Remarks
--------------------------------------------------------------------------------
Note (1): Each map was inspected for patterns of pairs or alignments of sources
across the central Seyfert. The sources which made up these patterns
were then identified by their C=cts/ks values and are referred to
by these numbers.
Note (2): + is East and - is West of the X-ray position
+ is North and - is South of the X-ray position
--------------------------------------------------------------------------------
(End) Patricia Bauer [CDS] 24-Feb-1997