J/AJ/136/2782 Star formation efficiency in nearby galaxies (Leroy+, 2008)
The star formation efficiency in nearby galaxies:
measuring where gas forms stars effectively.
Leroy A.K., Walter F., Brinks E., Bigiel F., De Blok W.J.G., Madore B.,
Thornley M.D.
<Astron. J., 136, 2782-2845 (2008)>
=2008AJ....136.2782L 2008AJ....136.2782L
ADC_Keywords: Galaxies, nearby ; H I data ; Radio lines
Keywords: galaxies: evolution - galaxies: ISM - radio lines: galaxies -
stars: formation
Abstract:
We measure the star formation efficiency (SFE), the star formation
rate (SFR) per unit of gas, in 23 nearby galaxies and compare it with
expectations from proposed star formation laws and thresholds. We use
HI maps from The HI Nearby Galaxy Survey (THINGS) and derive H2 maps
of CO measured by HERA CO-Line Extragalactic Survey and
Berkeley-Illinois-Maryland Association Survey of Nearby Galaxies. We
estimate the SFR by combining Galaxy Evolution Explorer (GALEX)
far-ultraviolet maps and the Spitzer Infrared Nearby Galaxies Survey
(SINGS) 24um maps, infer stellar surface density profiles from SINGS
3.6um data, and use kinematics from THINGS.
Description:
We assemble maps and radial profiles of the necessary quantities in 23
nearby, star-forming galaxies that we list in order of increasing
stellar mass in Table 2. These are galaxies for which we could compile
the necessary data, which means the overlap of THINGS, SINGS, the
GALEX Nearby Galaxy Survey (NGS), and (for spirals) either BIMA SONG
or HERACLES.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 34 23 Sample galaxies
table4.dat 80 23 Properties of sample galaxies
table7.dat 82 687 Table of radial profiles
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See also:
J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Galaxy (1)
9 A1 --- n_Name [e] e for IR data from Spitzer archive (not SINGS)
12- 13 I2 arcsec Res Angular resolution to match working spatial
resolution in the subsample, 400pc for dwarf
galaxies and 800pc for spirals
15- 23 A9 --- CO Origin of CO data
25- 26 A2 --- RC Rotation curve data (2)
28- 34 A7 --- Also Also in Sample of (3)
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Note (1): In order of increasing stellar mass.
Note (2): Rotation curve data code as follows:
dB = de Blok et al. (2008AJ....136.2648D 2008AJ....136.2648D)
T = only THINGS first moment (Walter et al., 2008 Cat. J/AJ/136/2563)
Note (3): Sample codes as follows:
1 = Kennicutt (1989ApJ...344..685K 1989ApJ...344..685K)
2 = Martin & Kennicutt (2001ApJ...555..301M 2001ApJ...555..301M)
3 = Wong & Blitz (2002ApJ...569..157W 2002ApJ...569..157W)
4 = Boissier et al. (2003MNRAS.346.1215B 2003MNRAS.346.1215B)
5 = Blitz & Rosolowsky (2006ApJ...650..933B 2006ApJ...650..933B)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Galaxy name
10- 13 F4.1 Mpc Dist Distance
15- 16 I2 deg i Inclination
18- 20 I3 deg PA Position angle
22- 25 A4 --- MType Morphological type
27- 31 F5.1 mag BMAG Absolute B magnitude
33- 36 F4.1 kpc r25 B-band isophotal radius at 25mag/arcsec2
38- 40 I3 km/s vflat ?=- Free velocity parameter for our rotation
curve fit
42- 45 F4.1 kpc lflat ?=- Free scale length parameter for our rotation
curve fit
47- 50 F4.1 [Msun] logM* Stellar mass
52- 55 F4.1 [Msun] logMHI HI mass
57- 58 A2 --- l_logMH2 [≤ ] Limit flag on logMH2 (Upper limits are at
5σ significance)
59- 61 F3.1 [Msun] logMH2 ?=- H2 mass
62 A1 --- n_logMH2 [a] Note on logMH2 (1)
64- 68 F5.3 Msun/yr SFR Star formation rate
70- 72 F3.1 kpc l* Scale length derived from exponential fits to
the Σ* profile
74- 76 F3.1 kpc lSFR Scale length derived from exponential fits to
the ΣSFR profile
78- 80 F3.1 kpc lCO ?=- Scale length derived from exponential fits
to the ΣH2(CO) profile
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Note (1): Unless noted logMH2 comes from
* HERACLES (Leroy et al. 2008AJ....136.2782L 2008AJ....136.2782L) or
* BIMA SONG (Helfer et al. 2003ApJS..145..259H 2003ApJS..145..259H).
* NGC 3077 is from Walter et al. (2001AJ....121..727W 2001AJ....121..727W) and
* NGC 4449 is from Bolatto et al. (2008, Cat. J/ApJ/686/948).
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Galaxy name
10- 13 F4.1 kpc r Galactocentric radius of ring center
15- 18 F4.2 --- r.n Normalized galactocentric radius
(to r25) of ring center
20- 24 F5.2 Msun/pc2 SigmaHI ? Surface density of H I (2)
26- 28 F3.1 Msun/pc2 e_SigmaHI rms uncertainty in SigmaHI (3)
30- 35 F6.2 Msun/pc2 SigmaH2 ? Surface density of H2 (2)
37- 40 F4.1 Msun/pc2 e_SigmaH2 ? RMS uncertainty in SigmaH2
42- 48 F7.1 Msun/pc2 Sigma* Surface density of stars
50- 54 F5.1 Msun/pc2 e_Sigma* rms uncertainty in Sigma* (3)
56- 62 F7.2 10-4Msun/yr/kpc2 FUV+24 ? Total star formation rate
surface density
64- 68 F5.1 10-4Msun/yr/kpc2 e_FUV+24 rms uncertainty in FUV+24
70- 75 F6.2 10-4Msun/yr/kpc2 FUV ? FUV portion of star formation
rate surface density
77- 82 F6.1 10-4Msun/yr/kpc2 24 ? 24 micron portion of star
formation rate surface density
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Note (2): Including helium.
Note (3): 1.0 = upper limit.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 18-Jun-2011