J/AJ/150/94 Chandra Local Volume Survey. I. (Binder+, 2015)
The Chandra Local Volume Survey. I. The X-ray point source populations of
NGC 55, NGC 2403, and NGC 4214.
Binder B., Williams B.F., Eracleous M., Plucinsky P.P., Gaetz T.J.,
Anderson S.F., Skillman E.D., Dalcanton J.J., Kong A.K.H., Weisz D.R.
<Astron. J., 150, 94 (2015)>
=2015AJ....150...94B 2015AJ....150...94B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; X-ray sources ; Binaries, X-ray
Keywords: galaxies: individual: (NGC 55,NGC 2403,NGC 4214) - surveys -
X-rays: binaries - X-rays: galaxies
Abstract:
We present comprehensive X-ray point source catalogs of NGC55,
NGC2403, and NGC4214 as part of the Chandra Local Volume Survey. The
combined archival observations have effective exposure times of
56.5ks, 190ks, and 79ks for NGC55, NGC2403, and NGC4214, respectively.
When combined with our published catalogs for NGC300 and NGC404, our
survey contains 629 X-ray sources total down to a limiting unabsorbed
luminosity of ∼5x1035erg/s in the 0.35-8keV band in each of the five
galaxies. We present X-ray hardness ratios, spectral analysis, radial
source distributions, and an analysis of the temporal variability for
the X-ray sources detected at high significance. To constrain the
nature of each X-ray source, we carried out cross-correlations with
multi-wavelength data sets. We searched overlapping Hubble Space
Telescope observations for optical counterparts to our X-ray
detections to provide preliminary classifications for each X-ray
source as a likely X-ray binary, background active galactic nucleus,
supernova remnant, or foreground star.
Description:
In this paper, we present the X-ray point source catalogs from
archival Chandra observations of NGC55, NGC2403, and NGC4214 and
compare these catalogs to those of NGC300 and NGC404.
We constructed the X-ray point source catalogs of NGC55, NGC2403, and
NGC4214 using archival Chandra ACIS data. NGC55 was observed by
Chandra on 2001 Sep 11 (ID 2255), and on 2004 Jun 29 (ID 4744).
NGC2403 was observed by Chandra on 17 Apr 2001 (ID 2014), on 2004 Aug
9 (ID 4627), on 2004 Aug 23 (ID 4628), on 2004 Oct 3 (ID 4629), and on
2004 Dec 22 (ID 4630). NGC4214 was Chandra observed on 2001 Oct 16 (ID
2030), on 2004 Apr 3 (ID 4743), and on 2004 July 30 (ID 5197).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
galaxies.dat 41 5 Galaxies sample from Chandra Local Volume Survey (CLVS)
table5.dat 94 967 Expanded X-ray source lists for all galaxies in
the Chandra Local Volume Survey
table8.dat 35 460 Hardness ratios of X-ray sources
table13.dat 23 205 Long-term variability of X-ray sources from Chandra
observations
fluxes.dat 156 213 Long-term variability data for X-ray sources
(tables 14--16 of the paper)
table17.dat 117 99 Public multiwavelength data for NGC 55 X-ray sources
table18.dat 117 146 Public multiwavelength data for NGC 2403 X-ray sources
table19.dat 117 92 Public multiwavelength data for NGC 4214 sources
table20.dat 91 460 Final X-ray source classification
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
B/hst : HST Archived Exposures Catalog (STScI, 2007)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
J/ApJ/763/128 : Chandra Local Volume Survey: NGC 404 sources (Binder+, 2013)
J/ApJ/758/15 : Chandra X-ray point sources of NGC 300 (Binder+, 2012)
J/ApJS/193/31 : M33 Chandra ACIS survey: final catalog (Tullmann+, 2011)
J/AJ/133/917 : HST photometry of two NGC 4214 clusters (Ubeda+, 2007)
J/MNRAS/370/25 : XMM observations of NGC 55 (Stobbart+, 2006)
Byte-by-byte Description of file: galaxies.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 300, 404,
2403, and 4214)
6- 9 F4.2 Mpc Dist [2/3.3] Distance
11 A1 --- r_Dist [abc] Reference for distance (1)
13- 20 A8 --- MType Morphological type from de Vaucouleurs
(1991rc3..book.....D 1991rc3..book.....D)
22- 23 I2 h RAh Hour of Right Ascension (J2000) (2)
25- 26 I2 min RAm Minute of Right Ascension (J2000) (2)
28- 31 F4.1 s RAs Second of Right Ascension (J2000) (2)
33 A1 --- DE- Sign of the Declination (J2000) (2)
34- 35 I2 deg DEd Degree of Declination (J2000) (2)
37- 38 I2 arcmin DEm Arcminute of Declination (J2000) (2)
40- 41 I2 arcsec DEs Arcsecond of Declination (J2000) (2)
--------------------------------------------------------------------------------
Note (1): The flags for reference are defined as follows:
a = Tikhonov et al. (2005A&A...431..127T 2005A&A...431..127T);
b = Dalcanton et al. (2009ApJS..183...67D 2009ApJS..183...67D);
c = Freedman & Madore (1988ApJ...332L..63F 1988ApJ...332L..63F).
Note (2): From NED.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 300, 404, 2403,
4214)
6- 8 I3 --- Xray [1/298] X-ray source running sequence number
9 A1 --- f_Xray [*] Indicates "marginally detected" source (1)
11- 28 A18 --- Name Source identifier (CXOLV JHHMMSS.ss+DDMMSS.s)
30- 39 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
41- 50 F10.6 deg DEdeg Declination in decimal degrees (J2000)
52- 55 F4.2 arcsec ePos [0.01/1.83] Positional error of the X-ray source
57- 60 F4.1 arcmin theta [0.3/18.5] Off-axis angle θ (2)
62- 68 F7.1 ct Ncts [-2.2/16601] Net counts detected in the
0.35-8keV energy band
70- 74 F5.1 ct E_Ncts [2.7/133] Upper uncertainty in Ncts
76- 80 F5.1 ct e_Ncts [1.3/132] Lower uncertainty in Ncts
82 A1 --- l_logP [<] Upper limit flag on logP
83- 87 F5.1 [-] logP [-26.2/-0.1] Log of 0.35-8keV Poisson
probability of not being a source
89- 94 F6.1 aW/m2 Flux [-0.4/1654] Unabsorbed 0.35-8keV flux predicted
for the X-ray source (in 10-15erg/s/cm2) (3)
--------------------------------------------------------------------------------
Note (1): Not included in subsequent analysis (see Section 4.1 in the paper for
further details).
Note (2): From the Chandra ACIS aim point. For sources that were detected during
multiple Chandra observations, the minimum off-axis angle is reported.
Note (3): Assuming the power law with Γ=1.9 absorbed by the appropriate
Galactic column given in Table1 (see the paper).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 2403, or 4214)
6- 8 I3 --- Xray [1/190] X-ray source running sequence number
10- 14 F5.2 --- HRs [-1/0.8]? Soft hardness ratio (1)
16- 19 F4.2 --- e_HRs [0.01/0.51]? Uncertainty in HRs
21- 25 F5.2 --- HRh [-0.8/0.8]? Hard hardness ratio (2)
27- 30 F4.2 --- e_HRh [0/0.5]? Uncertainty in HRh
32- 35 A4 --- Type Source type (ABS, BKG, HARD, SNR, SOFT, or XRB) (G1)
--------------------------------------------------------------------------------
Note (1): Soft is defined as (M-S)/(H+M+S) where S, M, and H are
the 0.35-1.1keV, 1.1-2.6keV, and 2.6-8keV band, respectively.
Note (2): Hard is defined as (H-M)/(H+M+S) where S, M, and H are
the 0.35-1.1keV, 1.1-2.6keV, and 2.6-8keV band, respectively.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table13.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 2403, or 4214)
6- 8 I3 --- Xray [2/190] X-ray source running sequence number
10- 16 F7.1 --- eta [5/16576] Variability threshold η (1)
18- 23 F6.1 --- Ratio [1/3255] Maximum to minimum flux ratio
--------------------------------------------------------------------------------
Note (1): The variability index defined by Tullmann et al. 2011
(cat. J/ApJS/193/31) and is sensitive to long-term variability. Only
sources ≥5, indicative of a variability between the individual Chandra
exposures, are shown.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fluxes.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 2403, or 4214)
6- 8 I3 --- Xray [2/190] X-ray source running sequence number
10- 16 F7.2 aW/m2 Flux1 [0.1/9592]? 0.35-8keV flux on 17 Apr. 2001 (1)
18 A1 --- l_Flux2 [<] Upper limit flag on Flux2
19- 25 F7.2 aW/m2 Flux2 [0.3/2611]? 0.35-8keV flux on 30 Apr. 2001 (2)
27 A1 --- l_Flux3 [<] Upper limit flag on Flux3
28- 34 F7.2 aW/m2 Flux3 [0.2/1512]? 0.35-8keV flux on 11 Sept. 2001 (3)
36 A1 --- l_Flux4 [<] Upper limit flag on Flux4
37- 42 F6.2 aW/m2 Flux4 [0.5/214]? The 0.35-8keV flux on 16 Oct. 2001 (4)
44 A1 --- l_Flux5 [<] Upper limit flag on Flux5
45- 51 F7.2 aW/m2 Flux5 ? The 0.35-8keV flux on 14 Nov. 2001 (5)
53 A1 --- l_Flux6 [<] Upper limit flag on Flux6
54- 60 F7.2 aW/m2 Flux6 ? The 0.35-8keV flux on 15 Nov. 2001 (6)
62 A1 --- l_Flux7 [<] Upper limit flag on Flux7
64- 69 F6.2 aW/m2 Flux7 [21/316]? The 0.35-8keV flux on 22 Nov. 2001 (7)
71 A1 --- l_Flux8 [<] Upper limit flag on Flux8
72- 78 F7.2 aW/m2 Flux8 [14/1259]? 0.35-8keV flux on 11 Sept. 2003 (8)
79- 84 F6.2 aW/m2 Flux9 [0.3/424]? The 0.35-8keV flux on 3 Apr. 2004 (9)
86 A1 --- l_Flux10 [<] Upper limit flag on Flux10
87- 93 F7.2 aW/m2 Flux10 [1/4408]? The 0.35-8keV flux on 29 June 2004 (10)
95-100 F6.2 aW/m2 Flux11 [0.2/197]? 0.35-8keV flux on 30 Jul. 2004 (11)
102-106 F5.2 aW/m2 Flux12 [4/95]? The 0.35-8keV flux on 9 Aug. 2004 (12)
108-114 F7.2 aW/m2 Flux13 [0.1/1330]? 0.35-8keV flux on 23 Aug. 2004 (13)
116 A1 --- l_Flux14 [<] Upper limit flag on Flux14
117-123 F7.2 aW/m2 Flux14 [2/1439]? 0.35-8keV flux on 12 Sept. 2004 (14)
125 A1 --- l_Flux15 [<] Upper limit flag on Flux15
126-131 F6.2 aW/m2 Flux15 [0.3/413]? The 0.35-8keV flux on 3 Oct. 2004 (15)
133 A1 --- l_Flux16 [<] Upper limit flag on Flux16
134-140 F7.2 aW/m2 Flux16 [0.2/1090]? 0.35-8keV flux on 22 Dec. 2004 (16)
142-148 F7.2 --- Ratio [1/3266]? Maximum to minimum flux ratio (uses
only source detection)
150 A1 --- l_Rupp [<>] Lower limit flag on Rupp
151-156 F6.1 --- Rupp [1.9/1006]? Upper limit on Ratio (G2)
--------------------------------------------------------------------------------
Note (1): In units of 10-15erg/s/cm2; MJD 52016; Chandra ObsID 2014
(see cat. B/chandra).
Note (2): In units of 10-15erg/s/cm2; MJD 52759; XMM-Newton ObsID 0150651101.
Note (3): In units of 10-15erg/s/cm2; MJD 52176; Chandra ObsID 2255.
Note (4): In units of 10-15erg/s/cm2; MJD 52198; Chandra ObsID 2030.
Note (5): In units of 10-15erg/s/cm2; MJD 52227; XMM-Newton ObsID 0028740201.
Note (6): In units of 10-15erg/s/cm2; MJD 52228; XMM-Newton ObsID 0028740101.
Note (7): In units 10-15erg/s/cm2; MJD 52235; XMM-Newton ObsID 0035940201.
Note (8): In units of 10-15erg/s/cm2; MJD 52893; XMM-Newton ObsID 0150651201.
Note (9): In units of 10-15erg/s/cm2; MJD 53098; Chandra ObsID 4743.
Note (10): In units of 10-15erg/s/cm2; MJD 53185; Chandra ObsID 4744.
Note (11): In units of 10-15erg/s/cm2; MJD 53216; Chandra ObsID 5197.
Note (12): In units of 10-15erg/s/cm2; MJD 53226; Chandra ObsID 4627.
Note (13): In units of 10-15erg/s/cm2; MJD 53240; Chandra ObsID 4628.
Note (14): In units of 10-15erg/s/cm2; MJD 53260; XMM-Newton ObsID 0164560901.
Note (15): In units of 10-15erg/s/cm2; MJD 53281; Chandra ObsID 4629.
Note (16): In units of 10-15erg/s/cm2; MJD 53361; Chandra ObsID 4630.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1[789].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Xray [1/190] X-ray source running sequence number
5- 7 I3 --- HST1 [0/255]? First number of Hubble Space Telescope
(HST) matches (G3)
9- 10 I2 --- HST2 [0/25]? Second number of HST matches (G3)
12- 25 A14 --- SType Simbad counterpart type (G4)
27- 31 F5.2 mag B1mag [8.8/21.1]? USNO-B1.0 B1 band magnitude
33- 37 F5.2 mag R1mag [8.1/21.3]? USNO-B1.0 R1 band magnitude
39- 43 F5.2 mag B2mag [8.6/21.8]? USNO-B1.0 B2 band magnitude
45- 49 F5.2 mag R2mag [8/24.2]? USNO-B1.0 R2 band magnitude
51- 55 F5.2 mag Imag [7.8/23.5]? USNO-B1.0 I band magnitude
57- 61 F5.2 mag umag [17.8/26.2]? SDSS u band magnitude
63- 68 F6.2 mag gmag [16.6/121.9]? SDSS g band magnitude
70- 74 F5.2 mag rmag [15.4/23.7]? SDSS r band magnitude
76- 81 F6.3 mag imag [14.8/23]? SDSS i band magnitude
83- 87 F5.2 mag zmag [14.4/22.9]? SDSS z band magnitude
89- 93 F5.2 mag Jmag [7.4/16.9]? 2MASS J band magnitude
95- 99 F5.2 mag Hmag [7.2/16.3]? 2MASS H band magnitude
101-105 F5.2 mag Kmag [7.1/20.3]? 2MASS Ks band magnitude
107-111 F5.2 mag FUV [10.8/25]? GALEX-GR6 Far-UV band magnitude
113-117 F5.2 mag NUV [10.4/24.9]? GALEX-GR6 Near-UV band magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table20.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [55/4214] Galaxy NGC number (55, 2403, or 4214)
6- 8 I3 --- Xray [1/190] X-ray source running sequence number
10- 13 A4 --- Hcl Class from hardness ratios (ABS, HARD, SNR,
SOFT, or XRB) (G1)
15- 18 F4.1 kpc Dist [0/16.5] Galactocentric distance
20 A1 --- A [Y] Indicates a source that appears associated
with the galaxy (i.e., coincident with a
spiral arm) (Y=Yes)
22- 31 A10 --- Var Variability description (rapid and/or long) (3)
33- 41 A9 --- Fit X-ray spectrum fit (apec, brems, diskbb, long,
2apec, po) (4)
43- 48 A6 --- Rcl Source class as determined by the X-ray to
optical flux ratio (AGN, HMXB, HMXB?, PL=1.4,
apec, po) (G1)
50- 67 A18 --- Obs Multiwavelenth observations available (FUV,
NUV, IR, or/and optical)
69- 82 A14 --- SType SIMBAD counterpart type (G4)
84- 91 A8 --- Fcl Our final classification (star, AGN, AGN?,
BH-LMXB?, HMXB, HMXB?, LMXB, LMXB?, SNR, SNR?,
ULX, star, star?) (G1)
--------------------------------------------------------------------------------
Note (3): Indicates whether evidence for X-ray variability was observed and, if
so, what type.
Note (4): General shape the spectrum showed is defined as follows:
apec = Thermal emission model;
brems = Bremsstrahlung emission;
diskbb = Disk blackbody;
po = Power law.
--------------------------------------------------------------------------------
Global Notes:
Note (G1): The types are defined as follows:
apec = Thermal emission model;
po = Power law best-fit model;
ABS = Absorbed source;
AGN = Active galactic nucleus;
BH-LMXB? = Black hole-low-mass X-ray binary?;
BKG = Background active galactic nucleus;
HARD = Hard source;
HMXB = High-mass X-ray binary;
LMXB = Low-mass X-ray binary;
SNR = Supernova remnant;
SOFT = Soft source;
ULX = Ultraluminous X-ray source;
XRB = X-ray binary.
Note (G2): For some sources, there is a flux upper limit in an observation that
is below the faintest source detection; in these cases, we calculate a
lower limit on the flux ration from the lowest measured upper limit.
Note (G3): Number of potential optical HST sources falling within the Chandra
error circle.
Note (G4): SIMBAD counterparts are listed as follows:
SNR = supernova remnant;
radio = radio source;
H II = H II region;
Cl* = star cluster;
SN = supernova designation;
ROSAT = historically known ROSAT source;
EINSTEIN = historically known Einstein source;
GC = globular cluster;
em. gal = emission-line galaxy;
gal. group = galaxy group;
RS CVN = cataclysmic variable.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 23-Feb-2016