ADS Astronomy Abstract Service
Title: The Einstein Slew Survey
Authors: ELVIS, MARTIN; PLUMMER, DAVID; SCHACHTER, JONATHAN;
FABBIANO, G.
Affiliation: AD(Harvard-Smithsonian Center for Astrophysics,
Cambridge, MA)
Journal: Astrophysical Journal Supplement Series (ISSN
0067-0049), vol. 80, no. 1, May 1992, p. 257-303.
Publication Date: 05/1992
Category: Astronomy
Origin: STI
NASA/STI Keywords: ASTRONOMICAL CATALOGS, SKY SURVEYS (ASTRONOMY), X RAY
SOURCES, ASTRONOMICAL MAPS, BL LACERTAE OBJECTS, HEAO
2
Bibliographic Code: 1992ApJS...80..257E
Abstract
A catalog of 819 sources detected in the Einstein IPC Slew Survey of the
X-ray sky is presented; 313 of the sources were not previously known as
X-ray sources. Typical count rates are 0.1 IPC count/s, roughly equivalent
to a flux of 3 x 10 exp -12 ergs/sq cm s. The sources have positional
uncertainties of 1.2 arcmin (90 percent confidence) radius, based on a
subset of 452 sources identified with previously known pointlike X-ray
sources (i.e., extent less than 3 arcmin). Identifications based on a number
of existing catalogs of X-ray and optical objects are proposed for 637 of
the sources, 78 percent of the survey (within a 3-arcmin error radius)
including 133 identifications of new X-ray sources. A public identification
data base for the Slew Survey sources will be maintained at CfA, and
contributions to this data base are invited.
January 1994
This directory contains the latest version of the Slew Survey
catalog, using the improvements described in the published version
(Elvis et al. 1992, ApJS, 80, 257), and advances since then. We provide
basic source detection information (positions, fluxes, and reliabilities),
updates on identifications with counterparts (from optical spectroscopy,
multiwavelength data, and published Slew Survey articles). These files
are included:
o apj.tbl: Basic Slew Survey source catalog, machine-readable
version very similar to published one (Table 6 of Elvis et
al. 1992). The main difference is that 10 spurious sources
have been cut -- they were actually just detections of
extended emission associated with the Cygnus Loop supernova
remnant. Sorted in order of increasing RA. Individual
column data is given below.
o apjcut.tbl: Machine readable information for the 10 spurious sources
cut from the published version.
o apsort.tbl: Same as "apj.tbl," except sorted by Slew Survey
name (1ES...), instead of RA, so corresponds to ordering
in "multi.tbl".
o multi.tbl: Updated optical identification and multiwavelength
information for the sources in "apjs.tbl". We include radio,
IRAS, and optical magnitudes. We also provide Galactic
coordinates for convenience. Sorted by Slew Survey name.
Invididual column data is given below.
o notes.ids: Notes on individual identifications described
in "multi.tbl," drawing on our multiwavelength information
described in multi.tbl, and ROSAT all--sky survey data
(to be published elsewhere).
o refs.txt: List of published papers containing Slew Survey
optical identification information. The papers in preparation
will ultimately go beyond the information provided in "multi.tbl".
We include papers written by members of the Slew Survey team,
and by outside authors.
o obs.dat: List of Slew Survey fields for which we have
performed optical spectroscopy to date. These observations
will ultimately progress the Slew Survey to being 100%
identified.
---- AP*.TBL: individual column information ----
(Relevant to "apj.tbl", "apjcut.tbl", and "apsort.tbl")
Bytes Type C format Parameter*
1-12 CHAR*12 %12s 1ES Name
13-21 CHAR*9 %9s RA1950 ( HH MM SS)
22-31 CHAR*10 %10s DEC1950 ( +/-DD MM SS)
32-38 REAL*4 %7.2f IPC Count Rate
39-44 REAL*4 %+6.2f Pos. Count Rate Error
45-50 REAL*4 %+6.2f Neg. Count Rate Error
51-59 CHAR*9 %9s Num. Photons/Num. Slews
60 CHAR*1 %1s (space)
61-68 REAL*4 %5.2e P_rand
69-75 REAL*4 %7.2f Exposure time
76-78 INT*2 %3d mean PI bin
79-81 CHAR*2 %3s Qual., Image Codes
82-87 CHAR*6 %6s EMSS, EOSCAT info
88-91 CHAR*4 %4s EOSCAT offset (or " ...")
92-106 CHAR*15 %15s EXOSAT, HEAO--A1/A3 info
107-110 CHAR*4 %4s HEAO offset (or " ...")
111-114 CHAR*4 %4s Catalog of Counterparts
115-127 CHAR*13 %13s Counterpart Class.:Type/z
128-144 CHAR*17 %17s Counterpart Name
145-149 CHAR*5 %5s Cat. offset (or " ...")
Elvis et al. 1992 has definitions and detailed discussion of all parameters.
We summarize the definitions here, for the convenience of the reader.
All references to sections and figures are in Elvis et al. 1992,
e.g. ("paper Figure 7d"). Bibliographic references have been omitted
to save space.
Column 1: SOURCE NAME. `1ES' stands for first Einstein Slew Survey
catalog source. Coordinate names are based on the B1950.0 position
constructed from hours,minutes degrees,tenths of degrees, truncated
according to the IAU convention.
Columns 2 and 3: POSITION. In B1950.0 coordinates,
based on the percolation algorithm centroid. Where noted positions
have been refined by changing the percolation length as discussed in paper
Section 4.5. Errors on position are primarily systematic, arising from the
aspect solution. A 90% error radius of 1.2 arcminutes and a 95% radius
of 3.0 arcminutes are estimated from paper Figure 7d.
Column 4: COUNT RATE. Mean count rate in all PI bins
(1-15). This is on average a factor 1.19 larger than the standard
IPC `broad band' count rate (based on PI channels 2---10) used in the
2E catalog (see paper Section 5). Counts are taken from a 6 arcmin
on a side box centered on the percolation algorithm centroid. Background
counts scaled for exposure and area from a 30 arcmin on a side box (background
region 2) have been subtracted. Errors represent a 1 sigma confidence interval.
When total source plus background in the source box had less than
100 counts the error bars are based on a Poisson probability,
distribution as computed in Kraft (1991), which gives
asymmetric error bars. For sources with a larger number of photons a
Gaussian approximation was used.
Column 5: NUMBER OF PHOTONS (NP) in the 6 arcminute on a
side box and NUMBER OF SLEWS (NS) that contribute photons to
the object. Other slews may have passed over the source positions but
yielded no photons.
Column 6: PROBABILITY, P_rand. Probability of
finding the number of photons listed in column 5 relative
to background region 2. Small numbers indicate a higher chance that
the source is real. Values of P_rand < 1.0e-10 are listed
as equal to 1.0e-10. A threshold of log(P_rand) = -3.95 was used to
generate the list of accepted sources.
Column 7: EXPOSURE. Total Slew exposure time averaged over the
6 arcminue on a side box used in column 3.
Column 8: MEAN PULSE HEIGHT bin. The average of the
`pulse invariant' (PI, Harnden et al. 1984) channel numbers (1--15)
for each photon, which coarsely indicates the source spectrum.
Column 9: QUALITY CONTROL INDEX (Q) and IMAGE CODE (I).
The Q (1, 2, or 3; 3 being highest quality) value is a visual estimate
of the reliability of the source.
The IMAGE CODE highlights cases where Prob1/Prob2 (defined in paper Section
4.3) is large (> 10^3), and which a visual inspection shows to be
extended, or to have multiple sources within 15 arcmin (see paper Section 4.5).
The IMAGE CODE has the following values:
A --- Generally acceptable Prob1/Prob2;
E --- Extended source (> 15 arcmin);
M --- Multiple sources within 15 arcmin;
P --- Part of source (extended source existing in
more than one field).
Columns 10 and 11: EOSCAT NUMBER, Einstein EXTENDED MEDIUM
SURVEY MEMBERSHIP (noted by "m" ), and OFFSET FROM EOSCAT
POSITION (Delta 2E). For sources with counterparts in the 2E Catalog
(Harris et al. 1991), we provide the EOSCAT number and the difference
between the Slew and catalog positions, in arc minutes.
In addition, Medium Survey (Gioia et al. 1990, Stocke et al. 1991)
sources are noted with a letter "m" preceding the EOSCAT number.
Columns 12 and 13: HEAO---1 A3 COUNTERPART,
EXOSAT DETECTIONS (noted by "x" ), and OFFSET FROM HEAO---A3
POSITION (Delta 1H). For sources with counterparts in the HEAO---1
A3 catalog (Remillard et al. 1991), we provide the `1H' name and the
difference between the Slew and catalog positions, in arc minutes. In addition,
EXOSAT sources are noted with a letter "x" preceding the 1H name.
Columns 14---17: OPTICAL CATALOG (Cat.), OBJECT CLASSIFICATION
(Class.), COUNTERPART NAME (Name), and OFFSET FROM CATALOG POSITION (Delta C).
For sources with counterparts in (mainly) optical catalogs searched to
date (see below for catalog list and references), we provide the name
of the catalog, the classification (e.g., AGN), the counterpart name,
and the difference between the Slew and catalog positions, in arc minutes.
If the redshift or stellar spectral type is known, it is listed after
the object classification in column 15.
Composite spectral types indicate a binary (or other multiple star system).
In general, we have tried to use the most common names of objects.
For cases in which two objects (most commonly an SAO star
and an extragalactic object) were found in the same error box we
compared their f_x/f_opt ratios with those for the Medium
Survey sources (Maccacaro et al. 1988). In most cases only one of the
objects was a plausible counterpart given these ratios.
Cases in which more than one object is a likely counterpart
are indicated with asterisks, and noted below (Section 7.3).
If the counterpart name is the same as the Slew name in column 1, and
the catalog is well known, only the catalog designator is listed in
Column 16 (e.g., PG, EXO, 2E). Woolley names with letters A, B, ...
indicate multi-star systems (e.g., WLY 127AB). For each of the newly
discovered X-ray sources, we list all the names known to us in Table 7.
Abbreviations for names of catalogs are:
2E---Second IPC Catalog (`EOSCAT', Harris et al. 1991);
A3--- HEAO---A3 Catalog (Remillard et al. 1991);
ABL---Abell Catalog Abell Catalog (1958, Struble and
Rood 1987) and Southern Abell Catalog (Abell, Corwin, and Olowin 1989);
BMC---Bradt and McClintock (1983);
BSC---Bright Star Catalog (Hoffleit and Jaschek 1982);
EXO--- EXOSAT Database of optical and other
astronomical catalogs;
GCV---General Catalog of Variable Stars (Kholopov et al. 1985-1988);
HB---Hewitt and Burbidge (1986);
HD---Henry Draper Catalog (Cannon and Pickering 1918--1924);
MCS---McCook and Sion (1986);
MS--- Extended Medium Sensitivity Survey (Gioia et al. 1990);
RNG---Revised NGC Catalog (Sulentic and Tifft 1973);
WFC---ROSAT Wide Field Camera (Cooke 1991);
SAO---SAO Catalog (SAO Staff 1966);
SBD---SIMBAD database;
SHA---Shara (1990);
UGC---Uppsala General Catalogue of Galaxies (Nilsson 1973);
VV---Veron-Cetty and Veron (1987);
WLY---Woolley Catalog (Woolley et al. 1970);
This is an extended version of the Gleise catalog, using the
same numbering scheme as Gleise. ;
ZCT---CfA Redshift Catalog, Huchra (1990).
Abbreviations for object classification are:
AC---active star,
AGN---active galactic nucleus,
BL---BL Lac object,
CG---cluster of galaxies,
CV---cataclysmic variable,
GAL---normal galaxy,
P---pulsar,
S---normal star,
SNR---supernova remnant,
WD--white dwarf,
XRB--X-ray binary,
(XRB-Be)---X-ray binary (with Be star secondary).
---- NOTES ON INDIVIDUAL OBJECTS in "AP*.TBL" FILES ----
N.B. See "multi.tbl" and "notes.ids" for updates.
1ES0013+195: The error box also contains G 32 -7 (S:M4.5),
but at V=14 (cf. 13 for G 32 -6) it is an unlikely counterpart
based on f_x/f_opt (Maccacaro et al. 1984).
1ES0100+405: The stars G132 -51B and G132 -51C
are in the error box and have acceptable f_x/f_opt ratios,
although both (at V=13.01 ) are 2.2 magnitudes fainter than G 132 -51A.
1ES0120+004: Besides the star, the error box contains
MCG +00-04-103, a 16th magnitude galaxy which may be an AGN.
1ES0122+084A and B: Besides the cluster, the error box also
includes the galaxy UGC 977, which may be a previously unknown AGN.
1ES0237-531: The error box also contains SAO 232842 (S:K5),
which at V=8.3 is 0.9 magnitudes fainter than HD 16699.
1ES0255+128: Besides the cluster, the error box also
contains the galaxy UGC 2438, another possible AGN.
1ES0305-284: The error box also contains LTT 1477 (S:M3),
but this source has V=14, and can be ruled out by f_x/f_opt arguments.
1ES0315+681: The error box also contains SAO 12702 (S:M0).
1ES0316+413: Besides the cluster, the error box also
contains the AGN NGC 1275, a known X-ray source.
1ES0429+130: The error box also contains HD 286839 (S:K0).
1ES0538-019: In addition to HD 37742, the brightest in the field
(V=1.75), the field also has HD 37743 (S: B0III; V=4.2) and BD-02 1338C
(V=10.0).
1ES0702+646: Other than the AGN, the error box contains
SAO 14073 (S: G0).
1ES0716-248: The error box contains a substantial portion
of the globular cluster N2362, of which HD 57061 is the brightest star
(at V=4.32). There are more than 30 other possible counterparts, ranging
from V=8.12 to V=13, with known spectral types B2-A0.
1ES0924+232: In addition to the galaxy, there are at least
3 other galaxies in the error box. One of these, 0924+2312,
has similar redshift (GAL:0.021) to U5037. The others are IC 0538,
MCG +04-22-055, MCG +04-22-059, and MCG +04-22-260.
1ES0953+693: The error box also contains 0953+6917, a
galaxy which may have an active nucleus.
1ES1035-268: Error box contains the compact group
HCG 048, which includes the galaxy counterpart.
1ES1101+384: The error box contains two identifications
based on the 2E catalog: Mkn 421 (BL), and 51 UMA (S: A3), but
the latter is 2.1 from the 1ES position. Mkn 421 is a well known
source at high energies (Wood et al. 1984) and is clearly the preferred
identification based on an HRI position (from "einline").
1ES1215+039: The source is a double galaxy.
1ES1254-172: The error box also contains 1254-1711 GAL:0.049),
a possible AGN.
1ES1259+289: The error box also contains 1259+2857 (GAL:0.030),
a possible AGN.
1ES1301-239: Error box also contains A3541 (CG).
1ES1351+695: Error box also includes MCG12.13.24 (AGN: 0.031).
With V=17, MCG12.13.24 is a marginally acceptable candidate based on
values of f_x/f_opt (Maccacaro et al. 1984). Mkn 279 is the preferred
identification based on an HRI position (in "einline").
1ES1503+017: The counterpart, N5486, is part of a galaxy
pair with the fainter N5486A (GAL: 0.007).
1ES1507_076: Error box also contains MKN 1394, a possible AGN.
1ES1549+203: There are two acceptable identifications: LB
906 (AGN), and SAO 084044 (S: G0), but the latter is 1.6 arcmin from
the 1ES position.
1ES1602+178: The UGC counterpart is a galaxy pair.
In addition, the error box contains an NGC pair at z ~ 0.035
and a Zwicky triple at z = 0.038.
1ES1702+457: The error box also contains two galaxies---1702+4544A
(GAL:0.061) and 1701+4544B (GAL:0.007).
1ES1704+545: Triple system (with WLY 9584B, F6V; Wool 9584C).
1ES1706+787: The error box also contains a Zwicky triple (1706+7842),
and another Zwicky galaxy.
1ES1714+574: Error box also includes NGC 6345 (GAL),
2.7 arcminutes from the 1ES position.
1ES1731-325: Error box also includes HD 159176
(S:O6V+O6V), possibly a member of the globular cluster.
1ES1753-290: The error box also contains HD 163247 (S:FOV).
1ES1821+643: Error box also includes K1-16 (WD: D0Z1),
which had an EXOSAT detection, (1.2 arcmin from the 1ES position).
However, the PI bin value (= 6) suggests that the AGN is the correct
identification, since white dwarfs typically have a mean PI bin of 2.
1ES1914+092: Error box also includes SAO 124466 (S: F0).
1ES1928+233: Other then the infrared source, the field
contains HD 344462 (S:F5) and HD 344461 (S:A0).
1ES2247+106: Other than the cluster, the error box
also contains MCG 2-58-21, a 16th magnitude galaxy which
is possibly an AGN.
1ES2311-430: The error box also contains 2311-4300 (GAL:0.056),
with the same redshift as the cluster, a possible AGN.
---- MULTI.TBL: individual column information ----
Bytes Type C format Parameter
1-12 CHAR*12 %12s 1ES Name
13-27 CHAR*15 %15s Counterpart Class.:Type/z
28-46 CHAR*19 %19s Counterpart Name
47-52 REAL*4 %6.2f IPC Count Rate
53-72 CHAR*20 %20s Other X-ray info
73-82 CHAR*10 %10s 6 cm flux (or upper lim.)
83-88 CHAR*6 %6s 6 cm spectral index
89-98 CHAR*10 %10s IRAS 12u flux
99-110 CHAR*12 %12s IRAS 25u flux
111-124 CHAR*14 %14s IRAS 60u flux
125-140 CHAR*16 %16s IRAS 100u flux
141-147 CHAR*7 %7s Magnitude (usually V)
148-159 CHAR*12 %12s Hubble GSC information
160-166 REAL*4 %7.2f Galactic longitude (LII)
167-173 REAL*4 %7.2f Galactic latitude (BII)
Throughout the table, an ellipsis ("...") is used to denote nondetections,
or sources for which we have no information. We used a nominal 3 arcminute
search radius throughout, more conservative than the 2 arcminute Slew survey
positional accuracy (95%) confidence quoted in Elvis et al. 1992.
The first four columns (1ES NAME, COUNTERPART CLASS:TYPE/Z, COUNTERPART
NAME, and IPC COUNT RATE) are as in Elvis et al. 1992 (and in "ap*.tbl").
However, many of the counterpart assignments have been updated since the
publication of Elvis et al. 1992, using the multiwavelength information
in this very table. We have plotted the error circles from radio, IRAS,
and ROSAT all--sky survey data, together with the Slew error circles,
and all available counterpart information. The current counterpart
data and multiwavelength data reflect this work. Sources in which the
TYPE was deduced by our program of optical spectroscopy (see "refs.txt")
have "(Sp)" added on to the TYPE, e.g. AGN(Sp).
OTHER X-RAY INFO is provided, as available, for sources with previous
X-ray detections, in the form "m(EOSCAT number),x(1H name)," where
m = source detected in the Einstein Extended Medium Sensitivity
Survey (EMSS).
EOSCAT number = catalog number of source detected in pointed observations
of the Einstein IPC.
x = source detected with EXOSAT.
1H name = name of source detected in HEAO--1 (A1/A3 work of Remillard
et al.)
6 CM FLUX (mJy) and 6 CM SPECTRAL INDEX are taken from coincidences with
sources in the Becker et al. 1991 catalog, the southern extension
of the Condon survey (Condon et al. 1991) kindly searched for us by J. Condon,
and the new far southern PMN catalog (Griffith and Wright 1993). We also
provide detected fluxes and upper limits from our VLA work (described in our
published paper on BL Lac objects, Schachter et al. 1993; see "refs.txt").
IRAS FLUXES (Jy) are from positional coincidences with sources in the IRAS
Point Source and Faint Source Catalogs. Fluxes for multiple sources are
set off by dashes.
MAGNITUDES are taken from the literature, and the SIMBAD and NED databases.
In HUBBLE GSC INFORMATION we provide a range of magnitudes (and specify
whether quasi-V or quasi-B magnitudes are given by an explicit "V" or "B")
for objects in the Hubble Guide Star Catalog falling in the Slew error
circle. Given the high spatial density of the GSC, most Slew fields are
expected to contain at least one GSC source, purely by chance. Therefore,
other criteria (e.g. UBV photometry) must be used to determine whether
the GSC sources are plausible counterparts.
References to "multi.tbl" documentation:
Becker, R.H., White, R.L., & Edwards, A.L. 1991, Ap.J.Supp., 75, 1.
Condon, J.J., Broderick, J.J., Seielstad, G.A. 1991, A.J.,102, 2041.
Griffith, M. R. & Wright, A. E., 1993, AJ, 105, 1666.