J/MNRAS/480/210 Star formation on LV dwarf galaxies (Lopez-Sanchez+, 2018)
The disc-averaged star formation relation for Local Volume dwarf galaxies.
Lopez-Sanchez A.R., Lagos C.D.P., Young T., Jerjen H.
<Mon. Not. R. Astron. Soc., 480, 210-222 (2018)>
=2018MNRAS.480..210L 2018MNRAS.480..210L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Star Forming Region ; H I data
Keywords: galaxies: dwarf - galaxies: irregular - galaxies: star formation -
galaxies: structure
Abstract:
Spatially resolved HI studies of dwarf galaxies have provided a wealth
of precision data. However these high-quality, resolved observations
are only possible for handful of dwarf galaxies in the Local Volume.
Future HI surveys are unlikely to improve the current situation. We
therefore explore a method for estimating the surface density of the
atomic gas from global HI parameters that are conversely widely
available. We perform empirical tests using galaxies with resolved HI
maps, and find that our approximation produces values for the surface
density of atomic hydrogen within typically 0.5dex of the true value.
We apply this method to a sample of 147 galaxies drawn from modern
near-infrared stellar photometric surveys. With this sample we confirm
a strict correlation between the atomic gas surface density and the
star formation rate surface density, which is vertically offset from
the Kennicutt-Schmidt relation by a factor of 10-30, and significantly
steeper than the classical N=1.4 of Kennicutt (1998ARA&A..36..189K 1998ARA&A..36..189K).
We further infer the molecular fraction in the sample of low surface
brightness, predominantly dwarf galaxies by assuming that the star
formation relationship with molecular gas observed for spiral galaxies
also holds in these galaxies, finding a molecular-to-atomic gas mass
fraction within the range of 5-15 per cent. Comparison of the data to
available models shows that a model in which the thermal pressure
balances the vertical gravitational field captures better the shape of
the ΣSFR-Σgas relationship. However, such models fail
to reproduce the data completely, suggesting that thermal pressure
plays an important role in the discs of dwarf galaxies.
Description:
To study the star formation relation in a comprehensive sample of
Local Volume dwarfs (M*<9M☉), low-mass late-type and LSB
galaxies, we employ data from various sources in the literature. In
this study, the samples of YJLK14 and KRDJ08 are amalgamated to form
the primary sample of galaxies since we have full access to their data
and computed parameters. Together they form a sample of 79 galaxies
with several properties. First, a morphology that ranges from some
low-mass ellipticals and high-mass lenticulars to many low-mass late
types and dwarf irregulars. A broad range in stellar mass,
6.5<log10(M*/M☉)<11, with a sample median of 8.3. This
sample is mostly dominated by low-mass late-type galaxies and dwarf
irregulars. Finally, the KJRD08 and YJLK14 samples conveniently trace
the main cosmic structures of the Southern hemisphere out to 10Mpc
(the Sculptor and Cen A group, respectively). MVPB12 is an amalgamated
Ks-band data set of newly observed galaxies and previous photometric
studies filtered to include only those galaxies for which a surface
brightness profile was successfully fitted, and for which the tip of
the red giant branch (TRGB) distance was reliably measured. In
addition to their own observations, MVPB12 sourced galaxy photometry
from Vaduvescu et al. (2005AJ....130.1593V 2005AJ....130.1593V, 34 galaxies), Vaduvescu &
McCall (2008A&A...487..147V 2008A&A...487..147V, 17 galaxies), and Fingerhut et al.
(2010ApJ...716..792F 2010ApJ...716..792F, 80 galaxies). The MVPB12 sample contains a total
of 66 star-forming dwarf irregulars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 145 Externally obtained properties required to
compute the surface densities for the KRDJ08
and YJLK14 NIR samples.
table2.dat 53 145 Computed quantities for the NIR catalogue
galaxies
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Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Sample Sample name
8- 19 A12 --- Name Galaxy name
21- 22 I2 h RAh ?=- Right Ascension (J2000)
24- 25 I2 min RAm ?=- Right Ascension (J2000)
27- 31 F5.2 s RAs ? Right Ascension (J2000)
33 A1 --- DE- ? Declination sign (J2000)
34- 35 I2 deg DEd ?=- Declination (J2000)
37- 38 I2 arcmin DEm ?=- Declination (J2000)
40- 43 F4.1 arcsec DEs ? Declination (J2000)
45- 46 A2 --- MType Morphology, using the classification scheme by
de Vaucouleurs et al. (1991, Cat. VII/155)
48- 52 F5.2 Mpc Dist Radial distance in Mpc (1)
54 A1 --- r_Dist ?=- Distance reference (2)
56- 59 A4 --- Method ?=- Derivation method of the radial distance
61- 65 F5.2 mag FUV ? Far-Ultraviolet Flux
67 A1 --- r_FUV ?=- FUV reference (3)
69- 73 F5.2 10-7W L(24um) ? 24µm luminosity
75- 79 F5.1 Jy.km/s FHI ? HI Flux
81 A1 --- r_FHI ?=- FHI reference (4)
83- 86 F4.2 mag AB B-band galactic extinction
88- 92 F5.2 mag Bmag ? Total observed luminosity in the B-band
94 A1 --- r_Bmag ?=- Bmag reference (5)
96- 99 F4.2 mag B-H ? B-H colour corrected for extinction
101-104 F4.2 mag B-Ks ? B-Ks colour corrected for extinction
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Note (1): Note that the obtained values have been rounded to the nearest
decimal place since distance derivation methods are typically no
more accurate than 10 per cent.
Note (2): References as follows:
a = Karachentsev et al. (2002A&A...385...21K 2002A&A...385...21K)
b = Karachentsev et al. (2003A&A...398..479K 2003A&A...398..479K, Cat. J/A+A/398/479)
c = Karachentsev et al. (2006AJ....131.1361K 2006AJ....131.1361K)
d = Karachentsev et al. (2007AJ....133..504K 2007AJ....133..504K, Cat. J/AJ/133/504)
e = Karachentsev, Makarov & Kaisina (2013AJ....145..101K 2013AJ....145..101K, Cat. J/AJ/145/101)
f = Tully et al. (2006AJ....132..729T 2006AJ....132..729T, Cat. J/ApJ/676/184)
g = Tully et al. (2008ApJ...676..184T 2008ApJ...676..184T, Cat. J/ApJ/676/184)
h = Karachentsev et al. (2003A&A...404...93K 2003A&A...404...93K)
i = Karachentsev et al. (2002A&A...389..812K 2002A&A...389..812K)
j = Karachentsev et al. (2000ApJ...542..128K 2000ApJ...542..128K)
k = Seth, Dalcanton & de Jong (2005AJ....129.1331S 2005AJ....129.1331S)
l = Roychowdhury et al. (2012MNRAS.426..665R 2012MNRAS.426..665R)
m = Cannon et al. (2003AJ....126.2806C 2003AJ....126.2806C)
n = Grise et al. (2008A&A...486..151G 2008A&A...486..151G)
o = Tosi et al. (2001AJ....122.1271T 2001AJ....122.1271T)
p = Tonry et al. (2001ApJ...546..681T 2001ApJ...546..681T)
q = Dalcanton et al. (2009ApJS..183...67D 2009ApJS..183...67D)
Note (3): References as follows:
a = GALEX (2017, Cat. II/335)
b = Lee et al. (2011ApJS..192....6L 2011ApJS..192....6L, Cat. J/ApJS/192/6)
Note (4): References as follows:
a = de Vaucouleurs et al. (1991, Cat. VII/155)
b = Lauberts & Valentijn (1989, Cat. VII/115)
c = Karachentsev, Makarov & Kaisina (2013AJ....145..101K 2013AJ....145..101K, Cat. J/AJ/145/101)
d = Metcalfe, Godwin & Peach (1994MNRAS.267..431M 1994MNRAS.267..431M)
e = Parodi, Barazza & Binggeli (2002A&A...388...29P 2002A&A...388...29P, Cat. J/A+A/388/29)
f = Jerjen, Freeman & Binggeli (2000AJ....119..166J 2000AJ....119..166J)
g = Warren, Jerjen & Koribalski (2007AJ....134.1849W 2007AJ....134.1849W)
h = Karachentsev et al. (2004AJ....127.2031K 2004AJ....127.2031K, Cat. J/AJ/127/2031)
i = Warren, Jerjen & Koribalski (2006AJ....131.2056W 2006AJ....131.2056W)
j = Kouwenhoven et al. (2007A&A...470..123K 2007A&A...470..123K)
k = Roychowdhury et al. (2012MNRAS.426..665R 2012MNRAS.426..665R)
Note (5): References as follows:
a = Doyle et al. (2005MNRAS.361...34D 2005MNRAS.361...34D, Cat. J/MNRAS/361/34)
b = Begum et al. (2008MNRAS.386.1667B 2008MNRAS.386.1667B)
c = Bouchard et al. (2005AJ....130.2058B 2005AJ....130.2058B)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Sample Sample name
8- 19 A12 --- Name Galaxy name
21- 25 F5.2 10-7W FUVcorr ? Far-Ultraviolet Flux corrected (1)
27- 31 F5.2 Msun/yr SFR ? Star Formation rate
33- 35 F3.1 Msun MHI ? Total HI mass in galaxy
37- 41 I5 pc R26.5eq Near-infrared equivalent Holmberg
radius
43- 47 F5.2 [Msun/pc2] logSigHI ? HI surface density
49- 53 F5.2 [Msun/yr/kpc2] logSigSFR ? Star formation rate surface density
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Note (1): The attenuation-corrected FUV luminosity, L(FUV)corr is given by
Hao et al. (2011ApJ...741..124H 2011ApJ...741..124H): L(FUV,corr)=L(FUV)+3.89L(25µm).
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 10-May-2022