J/AJ/142/170 ALFALFA survey: the α.40 HI source catalog (Haynes+, 2011)
The Arecibo Legacy Fast ALFA survey: the α.40 H I source catalog, its
characteristics and their impact on the derivation of the H I mass function.
Haynes M.P., Giovanelli R., Martin A.M., Hess K.M., Saintonge A.,
Adams E.A.K., Hallenbeck G., Hoffman G.L., Huang S., Kent B.R.,
Koopmann R.A., Papastergis E., Stierwalt S., Balonek T.J., Craig D.W.,
Higdon S.J.U., Kornreich D.A., Miller J.R., O'Donoghue A.A., Olowin R.P.,
Rosenberg J.L., Spekkens K., Troischt P., Wilcots E.M.
<Astron. J., 142, 170 (2011)>
=2011AJ....142..170H 2011AJ....142..170H
ADC_Keywords: Galaxies, radio ; Redshifts ; H I data ; Photometry, SDSS ;
Spectroscopy ; Surveys
Keywords: catalogs - galaxies: distances and redshifts -
galaxies: luminosity function, mass function - galaxies: spiral -
radio lines: galaxies; surveys
Abstract:
We present a current catalog of 21cm HI line sources extracted from
the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey
over ∼2800deg2 of sky: the α.40 catalog. Covering 40% of the
final survey area, the α.40 catalog contains 15855 sources in
the regions 07h30m<RA<16h30m, +04°<DEC<+16°, and
+24°<DEC<+28° and 22h<RA<03h, +14°<DEC<+16°, and
+24°<DEC<+32°. Of those, 15041 are certainly extragalactic,
yielding a source density of 5.3 galaxies per deg2, a factor of 29
improvement over the catalog extracted from the HI Parkes All-Sky
Survey. In addition to the source centroid positions, HI line flux
densities, recessional velocities, and line widths, the catalog
includes the coordinates of the most probable optical counterpart of
each HI line detection, and a separate compilation provides a
cross-match to identifications given in the photometric and
spectroscopic catalogs associated with the Sloan Digital Sky Survey
Data Release 7. Fewer than 2% of the extragalactic HI line sources
cannot be identified with a feasible optical counterpart; some of
those may be rare OH megamasers at 0.16<z<0.25. A detailed analysis is
presented of the completeness, width-dependent sensitivity function
and bias inherent of the α.40 catalog. The impact of survey
selection, distance errors, current volume coverage, and local
large-scale structure on the derivation of the HI mass function is
assessed.
Description:
Built and installed at Arecibo in 2004, the seven-beam radio "camera"
named ALFA (Arecibo L-band Feed Array) enable large-scale mapping
projects with the great sensitivity of the 305m telescope. ALFALFA
aims to cover 7074deg2 of the high Galactic latitude sky between
0° and 36° in declination, requiring a total of 4130hr of
telescope time. The catalog presented here, constituting 40% of the
expected final survey, supersedes previous ALFALFA data releases.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 15855 Properties of HI detections
table2.dat 289 6073 Comments on individual sources
table3.dat 76 12468 The ALFALFA-SDSS DR7 cross-reference
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VIII/77 : HI spectral properties of galaxies (Springob+, 2005)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/A+A/544/A65 : GALEX Arecibo SDSS survey. VI. (Catinella+, 2012)
J/AJ/139/2130 : ALFA-ZOA precursor observation (Henning+, 2010)
J/AJ/139/315 : HI-selected galaxies in SDSS. Optical data (West+, 2010)
J/AJ/138/338 : Arecibo legacy fast ALFA survey IX. (Stierwalt+, 2009)
J/ApJ/699/L43 : FIRST-NVSS-SDSS AGN sample catalog (Smolcic+, 2009)
J/A+A/458/341 : LSBG in Arecibo HI Strip Survey (Trachternach+, 2006)
J/AJ/113/1197 : 21cm Spectra (Haynes+ 1997)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- UGC/AGC [7/749512] Entry number in AGC (G1)
8- 15 A8 --- OName Common name of the Optical Counterparts (OCs)
17- 18 I2 h RAh Hour of right ascension (J2000) (1)
19- 20 I2 min RAm Minute of right ascension (J2000)
21- 24 F4.1 s RAs Second of right ascension (J2000)
25 A1 --- DE- Sign of the declination (J2000) (1)
26- 27 I2 deg DEd Degree of declination (J2000) (1)
28- 29 I2 arcmin DEm Arcminute of declination (J2000)
30- 31 I2 arcsec DEs Arcsecond of declination (J2000)
33- 34 I2 h RAOh ? Hour of right ascension (J2000) (2)
35- 36 I2 min RAOm ? Minute of right ascension (J2000)
37- 40 F4.1 s RAOs ? Second of right ascension (J2000)
41 A1 --- DEO- Sign of the declination (J2000) (2)
42- 43 I2 deg DEOd ? Degree of declination (J2000) (2)
44- 45 I2 arcmin DEOm ? Arcminute of declination (J2000)
46- 47 I2 arcsec DEOs ? Arcsecond of declination (J2000)
49- 53 I5 km/s cz [-470/17823] Heliocentric velocity of the HI
profile midpoint
55- 57 I3 km/s W50 [4/885] Observed velocity width at 50% of
peak on either side
59- 61 I3 km/s e_W50 [1/283] Error on W50
63- 68 F6.2 Jy.km/s Si(HI) [0.11/999.9] HI line flux
70- 73 F4.2 Jy.km/s e_Si(HI) [0/0.63] Error on Si(HI)
75- 79 F5.1 --- SNR [1.2/989.8] Ratio of peak flux to rms noise
81- 85 F5.2 mJy RMS [1.37/17.99] The rms noise in the extracted
spectrum at 10km/s resolution
87- 91 F5.1 Mpc Dist [0.3/259.6]? Adopted distance
93- 97 F5.2 [Msun] logM [3.76/10.94]? HI mass in logarithmic solar
units, where distance has been adopted
99 I1 --- HIc HI source quality code (G2)
101 A1 --- OCc Code for crossreference with SDSS (G3)
103 A1 --- T2 [*] Flag indicating entry in Table 2 (3)
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Note (1): Position of HI line source centroid
Note (2): Position of optical counterpart, where applicable
Note (3): * = a qualifying note is included in Table 2
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- UGC/AGC [7/749511] Entry number in AGC (G1)
8- 12 A5 --- ALFALFA Catalog identifier (N-NNN) from earlier
ALFALFA data releases, where applicable
15 A1 --- HIc HI source quality code (G2)
17-289 A273 --- Comm Note regarding HI source extraction and
optical counterpart assignment
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- UGC/AGC [7/749512] Entry number in AGC (G1)
8 I1 --- HIc HI source code (G2)
10 A1 --- OCc Code for crossreference with SDSS (G3)
12- 29 I18 --- ObjID The SDSS DR7 photometric catalog object
identification number, where available
31- 48 I18 --- SpObjID ? The SDSS DR7 spectroscopic catalog object
identification number, where available
50- 54 F5.2 mag rmag [10/24.77] The r-band model magnitude (1)
56- 60 F5.2 mag u-r [-5.14/13.22] The (u-r) color index associated
with the OC from the SDSS DR7 (2)
62- 68 F7.5 --- z [-0.00146/0.05973]? SDSS-DR7 redshift
70- 76 F7.5 --- e_z [0/0.0057]? Error on z
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Note (1): The r-band model magnitude of the optical counterpart (OC) from SDSS
DR7. Magnitudes correspond to the PhotoObjID or its SDSS parent
object.
Note (2): The color is not corrected for internal extinction or redshift.
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Global notes:
Note (G1): Arecibo General Catalog, a private database of extragalactic
objects maintained by M.P. Haynes and R. Giovanelli (ID≤12934 are
UGC numbers, in Simbad). See also Catalogs J/AJ/113/22
and J/AJ/113/1197
Note (G2): Code as follows:
1 = Source of significant S/N and high quality insuring reliability.
2 = Source of slightly lower S/N which coincides with an optical
counterpart of known, coincident redshift.
9 = Source without an optical counterpart whose velocity lies within
the range expected for Galactic disk or HVC emission.
Note (G3): Code as follows:
I = "identified". The PhotoObjID is set but no other indicative flags
have been applied; this code applies whether or not there is a SDSS
spectroscopic counterpart.
O = "outside DR7". The SDSS OC lies outside of the SDSS DR7 footprint
and thus no DR7 crossmatch can be performed.
U = "unidentified". No SDSS OC has been identified, but the object lies
within the SDSS DR7 footprint.
N = "no DR7 photometric ID". No SDSS DR7 photometric source has been
identified; assignment of this code can result from proximity to a
bright star, satellite trail, incomplete coverage or for other
reasons.
M = "missing". The OC is in the SDSS DR7 footprint region but neither a
PhotoObjID or a SpecObjID are returned to queries of the SDSS DR7
database.
P = "photometry suspect". The SDSS DR7 photometry for the associated
PhotoObjID are suspect for some reason as judged by the ALFALFA team.
Assignment of this code often is associated with the identification
of multiple near-equal-flux photometric objects within an obviously
single OC. Such cases apply often to very large optical objects or to
faint, low surface brightness and/or patchy systems. The optical
photometry associated with the SDSS "parent" object may be adequate
but caution should be exercised.
D = "displaced SDSS object". The SDSS Photo/SpectID is displaced from
the optical galaxy center, as identified by ALFALFA team. The
PhotoObjID may be legitimate; often this is brightest photometric
"child:". Because of the displacement, the SDSS redshift may not
reflect the systemic recessional velocity of the galaxy.
T = "two SDSS objects". The SDSS PhotoObjID associated with the galaxy
center is displaced from the target associated with the SDSS
SpectObjID, as judged by the ALFALFA team, i.e., the best PhotoObjID
does not coincide with the SpectObjID. Usually, the SpectObjID is an
offcenter HII region or other bright knot within the target galaxy.
S = "superposed SDSS object". The SDSS redshift corresponds to a
superposed foreground star or background QSO.
B = "bogus SDSS solution". The SDSS redshift is unreliable or rejected
for some unspecified reason.
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History:
From electronic version of the journal
References:
Giovanelli et al., Paper I 2005AJ....130.2598G 2005AJ....130.2598G
Giovanelli et al., Paper II 2005AJ....130.2613G 2005AJ....130.2613G, Cat. J/AJ/130/2613
Giovanelli et al., Paper III 2007AJ....133.2569G 2007AJ....133.2569G, Cat. J/AJ/133/2569
Saintonge, Paper IV 2007AJ....133.2087S 2007AJ....133.2087S
Saintonge et al., Paper V 2008AJ....135..588S 2008AJ....135..588S, Cat. J/AJ/135/588
Kent et al., Paper VI 2008AJ....136..713K 2008AJ....136..713K, Cat. J/AJ/136/713
Kent et al., Paper VII 2009ApJ...691.1595K 2009ApJ...691.1595K
Martin et al., Paper VIII 2009ApJS..183..214M 2009ApJS..183..214M, Cat. J/ApJS/183/214
Stierwalt et al., Paper IX 2009AJ....138..338S 2009AJ....138..338S, Cat. J/AJ/138/338
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Huang et al., Galaxy pop. 2012ApJ...756..113H 2012ApJ...756..113H
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 14-Mar-2013