J/ApJS/212/9 X-ray sources in Hickson Compact Groups (Tzanavaris+, 2014)
A Chandra-Swift view of point sources in Hickson Compact Groups: high AGN
fraction but a dearth of strong AGNs.
Tzanavaris P., Gallagher S.C., Hornschemeier A.E., Fedotov K.,
Eracleous M., Brandt W.N., Desjardins T.D., Charlton J.C., Gronwall C.
<Astrophys. J. Suppl. Ser., 212, 9 (2014)>
=2014ApJS..212....9T 2014ApJS..212....9T
ADC_Keywords: Active gal. nuclei ; X-ray sources
Keywords: catalogs; galaxies: active; galaxies: nuclei; ultraviolet: galaxies;
X-rays: galaxies
Abstract:
We present Chandra X-ray point source catalogs for 9 Hickson Compact
Groups (HCGs, 37 galaxies) at distances of 34-89Mpc. We perform
detailed X-ray point source detection and photometry and interpret the
point source population by means of simulated hardness ratios. We thus
estimate X-ray luminosities (LX) for all sources, most of which are
too weak for reliable spectral fitting. For all sources, we provide
catalogs with counts, count rates, power-law indices (Γ),
hardness ratios, and LX, in the full (0.5-8.0keV), soft
(0.5-2.0keV), and hard (2.0-8.0keV) bands. We use optical
emission-line ratios from the literature to re-classify 24 galaxies as
star-forming, accreting onto a supermassive black hole (AGNs),
transition objects, or low-ionization nuclear emission regions.
Two-thirds of our galaxies have nuclear X-ray sources with Swift/UVOT
counterparts. Two nuclei have LX,0.5-8.0keV>1042erg/s, are strong
multi-wavelength active galactic nuclei (AGNs), and follow the known
αOX-νLν(nearUV) correlation for strong AGNs.
Otherwise, most nuclei are X-ray faint, consistent with either a
low-luminosity AGN or a nuclear X-ray binary population, and fall in
the "non-AGN locus" in αOX-νLν(nearUV) space, which
also hosts other normal galaxies. Our results suggest that HCG X-ray
nuclei in high specific star formation rate spiral galaxies are likely
dominated by star formation, while those with low specific star
formation rates in earlier types likely harbor a weak AGN. The AGN
fraction in HCG galaxies with MR≤-20 and
LX,0.5-8.0keV≥1041erg/s is 0.08-0.01+0.35, somewhat higher
than the ∼5% fraction in galaxy clusters.
Description:
By virtue of their selection criteria, Hickson Compact Groups (HCGs)
constitute a distinct class among small galaxy agglomerations. The
Hickson catalog (Hickson et al. 1992, Cat. VII/213) comprises 92
spectroscopically confirmed nearby compact groups with three or more
members with accordant redshifts (i.e., within 1000km/s of the group
mean).
In this paper we present nine of these groups, for which both archival
Chandra X-ray and Swift UVOT ultraviolet data are available. An
observation log for the Chandra data is presented in Table 1. An
observation log for the Swift UVOT data is presented in Tzanavaris et
al. (2010ApJ...716..556T 2010ApJ...716..556T). In addition, note that in the present work
we have included UVOT data for HCGs 90 and 92.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 97 16 Chandra observation log for this Hickson Compact
Group (HCG) sample
table2.dat 109 1049 Derived quantities and detection codes for
X-Ray point sources
table3.dat 136 1049 Counts, count rates, and ACIS Extract (AE)
detection significance and no-source
probabilities for X-ray point sources
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
VII/213 : Hickson's Compact groups of Galaxies (Hickson+ 1982-1994)
J/A+A/565/A25 : Hickson compact groups Herschel observations (Bitsakis+, 2014)
J/A+A/542/A16 : X-ray detection of radio-selected SF galaxies (Ranalli+, 2012)
J/A+A/540/A96 : Molecular gas in HCGs (Martinez-Badenes+, 2012)
J/AJ/143/144 : ULX candidates in nearby Arp galaxies (Smith+, 2012)
J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)
J/A+A/533/A142 : UV-to-IR fluxes of Hickson compact groups (Bitsakis+, 2011)
J/ApJS/187/135 : SEDs of weak AGNs associated with LINERs (Eracleous+, 2010)
J/ApJS/187/64 : The simultaneous optical-to-X-ray SED of AGNs (Grupe+, 2010)
J/A+A/512/A34 : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)
J/AJ/130/387 : SDSS-ROSAT AGN data (Strateva+, 2005)
J/AJ/130/55 : Modelled Lick indices for galaxies (Mendes+, 2005)
J/ApJ/619/L95 : Star formation in Stephan's Quintet (Xu+, 2005)
J/A+A/435/521 : Radio Sources in Low-Luminosity AGNs. IV (Nagar+, 2005)
J/AJ/127/1811 : Catalog of SDSS compact groups of galaxies (Lee+, 2004)
J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)
J/ApJ/586/794 : Multiwavelength luminosities of galaxies (Bell, 2003)
J/A+AS/137/495 : Halpha Catalogue of HCG Galaxies (Severgnini+, 1999)
J/A+A/325/473 : HCG HI-deficiency (Huchtmeier 1997)
J/A+AS/117/39 : Hickson Compact Groups of Galaxies I. (Allam+, 1996)
J/ApJ/399/353 : Radial velocities in Hickson compact groups (Hickson+ 1992)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [HCG]
5- 6 I2 --- HCG [7/92] HCG number
8- 12 I5 --- ObsID ? Chandra observation number
14- 24 A11 "YYYY/MM/DD" Date Observation start date
26- 31 A6 --- Det Detector (ACIS -S or -I)
33- 37 F5.1 ks Texp [12.7/169.2] Exposure time
39 A1 --- f_Texp [*] *=Total exposure time for the HCG
41- 43 A3 --- Type Observation type (Guaranteed Observing Time
or General Observer proposal)
45- 54 A10 --- PI Principal Investigator
56- 77 A22 --- Aut Author's name of reference (first
publication using these data)
79- 97 A19 --- BibCode Bibcode
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- HCG [7/92] HCG catalog identifier
4- 6 I3 --- ID [1/256] Source identifier in HCG
7- 9 A3 --- f_ID [ A-GQ] Upper case letter(s) = galaxy
10 A1 --- n_ID [*] *: also a nuclear source
12- 15 F4.1 --- Gamma [-1.1/4.2] Power law index Γ
17- 19 F3.1 --- E_Gamma [0/5] Upper error in gamma
21- 23 F3.1 --- e_Gamma [0/2] Lower error in gamma
25- 29 F5.1 [mW/m2] FF [-16/-10.5]? Log full 0.5-8keV band flux;
in erg/s/cm^2 (1)
31- 33 F3.1 [mW/m2] e_FF ? Uncertainty in FF
35- 39 F5.1 [mW/m2] FS ? Log soft 0.5-2keV band flux; erg/s/cm^2 (1)
41- 43 F3.1 [mW/m2] e_FS ? Uncertainty in fS
45- 49 F5.1 [mW/m2] FH ? Log hard 2-8keV band flux; erg/s/cm^2 (1)
51- 53 F3.1 [mW/m2] e_FH ? Uncertainty if fH
55- 58 F4.1 [10-7W] LF [37/43]? Log full 0.5-8keV band luminosity;
in erg/s (1)
60- 63 F4.1 [10-7W] LS ? Log soft 0.5-2keV band luminosity; erg/s (1)
65- 68 F4.1 [10-7W] LH ? Log hard 2-8keV band luminosity; erg/s (1)
70- 74 F5.1 [mW/m2/Hz] F2keV [-35/-29]? Log flux density at 2keV;
in erg/s/cm^2/Hz (=1023Jy) (1)
76- 78 F3.1 [mW/m2/Hz] e_F2keV ? Uncertainty in F2keV
80- 81 I2 --- fHR [-2/1]? Hardness ratio detection code (G1)
83 I1 --- fF ? Full band detection code (G2)
85 I1 --- fS ? Soft band detection code, also in table3 (G2)
87 I1 --- fH ? Hard band detection code, also in table3 (G2)
89- 91 F3.1 --- EEF [0.4/0.9] Encircled Energy Fraction by AE
(ACIS Extract) PSF at 1.5keV
93-100 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
102-109 F8.4 deg DEdeg Declination in decimal degrees (J2000)
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Note (1): A blank indicates a -Inf value.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- HCG [7/92] HCG catalog identifier
4- 6 I3 --- ID [1/256] Source identifier
7- 9 A3 --- f_ID [ A-GQ] Upper case letter(s) = galaxy
11- 15 I5 ct cF [0/23361] Full 0.5-8 keV band counts
17- 19 I3 ct E_cF Upper error in cF
21- 23 I3 ct e_cF Lower error in cF
25 I1 --- f_cF ? Full band detection code (G2)
27- 30 I4 ct cS Soft 0.5-2 keV band counts
32- 33 I2 ct E_cS Upper error in cS
35- 36 I2 ct e_cS Lower error in cS
38 I1 --- f_cS ? Soft band detection code (G2)
40- 44 I5 ct cH Hard 2-8 keV band counts
46- 48 I3 ct E_cH Upper error in cH
50- 52 I3 ct e_cH Lower error in cH
54 I1 --- f_cH ? Hard band detection code (G2)
56- 60 F5.2 --- HR [-1/0.95] Hardness ratio (HR=(cH-cS)/(cH+cS))
62- 65 F4.2 --- E_HR [0/1.1] Upper error in HR
67- 70 F4.2 --- e_HR [0/1] Lower error in HR
72- 73 I2 --- f_HR [-2/1]? Hardness ratio detection code (G1)
75- 80 F6.2 ct/ks CRF [0/472] Full 0.5-8 keV band count rate
82- 85 F4.2 ct/ks E_CRF Upper error in CRF
87- 90 F4.2 ct/ks e_CRF Lower error in CRF
92- 96 F5.2 ct/ks CRS Soft 0.5-2 keV band count rate
98-101 F4.2 ct/ks E_CRS Upper error in CRS
103-106 F4.2 ct/ks e_CRS Lower error in CRS
108-113 F6.2 ct/ks CRH Hard 2-8 keV band count rate
115-118 F4.2 ct/ks E_CRH Upper error in CRH
120-123 F4.2 ct/ks e_CRH Lower error in CRH
125-130 E6.1 --- AEsig [-2/200] AE detection significance (2)
132-136 E5.1 --- AEP [0/1] AE no-source probability (2)
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Note (2): ACIS Extract (AE, Broos et al. 2010ApJ...714.1582B 2010ApJ...714.1582B; see section 3.1)
Sources with values of AEP<0.004 may be considered detections (section 3.2)
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Global notes:
Note (G1): Flag as follows:
0 = detection in both hard and soft bands;
-1 = detection in hard but not soft band; HR is a lower limit;
1 = detection in soft but not hard band; HR is an upper limit;
-2 = no detection in either hard or soft band.
Note (G2): Code as follows:
0 = detection in band;
1 = no detection in band because net counts <0;
5 = no detection in band because net counts - Gehrels 2σ error <0.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Jun-2014