J/ApJ/772/27 Paα (1.87um) LF of HII regions in 12 galaxies (Liu+, 2013)
The Paα luminosity function of H II regions in nearby galaxies from
HST/NICMOS.
Liu G., Calzetti D., Kennicutt R.C.JR, Schinnerer E., Sofue Y., Komugi S.,
Egusa F., Scoville N.Z.
<Astrophys. J., 772, 27 (2013)>
=2013ApJ...772...27L 2013ApJ...772...27L
ADC_Keywords: Galaxies, nearby ; Photometry, HST ; H II regions ;
Infrared sources
Keywords: galaxies: H II regions
Abstract:
The H II region luminosity function (LF) is an important tool for
deriving the birthrates and mass distribution of OB associations and
is an excellent tracer of the newly formed massive stars and
associations. To date, extensive work (predominantly in Hα) has
been done from the ground, which is hindered by dust extinction and
the severe blending of adjacent (spatially or in projection) H II
regions. Reliably measuring the properties of H II regions requires a
linear resolution <40pc, but analyses satisfying this requirement have
been done only in a handful of galaxies, so far. As the first
space-based work using a galaxy sample, we have selected 12 galaxies
from our HST/NICMOS Paα survey and studied the LF and size
distribution of H II regions both in individual galaxies and
cumulatively, using a virtually extinction-free tracer of the ionizing
photon rate. The high angular resolution and low sensitivity to
diffuse emission of NICMOS also offer an advantage over ground-based
imaging by enabling a higher degree of de-blending of the H II
regions. We do not confirm the broken power-law LFs found in
ground-based studies. Instead, we find that the LFs, both individual
and co-added, follow a single power law dN(L)/dlnL∝L-1, are
consistent with the mass function of star clusters in nearby galaxies,
and are in agreement with the results of the existing analyses with
Hubble Space Telescope (HST) data. The individual and co-added size
distributions of H II regions are both roughly consistent with
dN(D)/dlnD∝D-3, but the power-law scaling is probably
contaminated by blended regions or complexes.
Description:
The galaxies analyzed in this paper are selected from a recent
HST/NICMOS survey of the central ∼1' field of 84 nearby galaxies
evenly distributed across all Hubble and bar types (HST/GO-11080).
Targeting the redshifted hydrogen Paα emission line using the
NIC3 camera, these observations were completed in 2008 February. In
order to optimize our analysis, we downselect a subsample of 12 spiral
galaxies.
The 12 sample galaxies were observed between 2007 February 13 and 2008
February 3 with the NICMOS/NIC3 camera on board the HST. NIC3 images
have a 51"x51" FOV and a pixel scale of 0.2" with an undersampled
point-spread function (PSF). In this survey, each observation consists
of images taken in two narrowband filters: one centered on the
Paα hydrogen recombination line (1.87um, F187N) and the other on
the adjacent narrowband continuum (F190N).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 12 Characteristics of the sample galaxies and
their HST Paα data
table2.dat 51 1907 Catalog of the 1907 HII regions detected with
S/N≥3 in our sample of 12 galaxies
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See also:
VII/238 : HYPERLEDA. II. Homogenized HI data (Paturel+, 2003)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
VII/145 : Nearby Galaxies Catalogue (NBG) (Tully 1988)
J/A+A/551/A81 : NGC 6951 intensity and velocity maps (van der Laan+, 2013)
J/ApJ/756/117 : HyperLeda sample of nearby elliptical gal. (Focardi+, 2012)
J/ApJ/735/75 : HST observations of HII regions in M51 (Lee+, 2011)
J/AJ/142/139 : A new catalog of HII regions in M31 (Azimlu+, 2011)
J/AJ/141/113 : HII regions of M51 and NGC 4449 (Gutierrez+, 2011)
J/AJ/138/1938 : EDD: All Digital HI profile catalog (Courtois+, 2009)
J/AJ/138/332 : LEDA CMD/tip of the red giant branch (Jacobs+, 2009)
J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)
J/ApJ/671/333 : Aperture photometry in NGC 5194 (Kennicutt+, 2007)
J/A+A/459/L13 : A composite HII region luminosity function (Bradley+, 2006)
J/A+A/393/57 : Velocity field in the Local Group (Terry+, 2002)
J/A+A/354/823 : HII region catalogue of NGC 3359 (Rozas+, 2000)
J/PASP/111/685 : HII regions of M33. II. (Hodge+, 1999)
J/A+AS/135/145 : HII region catalogue of NGC 7479 (Rozas+, 1999)
J/A+AS/131/317 : NGC 7331 HII regions catalogue (Petit 1998)
J/MNRAS/297/255 : HII region catalogue of M100 (Knapen, 1998)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
J/AJ/104/92 : HII Regions Properties in M101 (Scowen+ 1992)
http://edd.ifa.hawaii.edu/ : The Extragalactic Distance Database home page
http://leda.univ-lyon1.fr/ : HyperLeda database
http://ned.ipac.caltech.edu/ : NASA/IPAC Extragalactic database (NED)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Galaxy name
9- 25 A17 --- Morph Morphological type from NED
27- 29 F3.1 --- TT [2/7] numerical Hubble type (as defined in
de Vaucouleurs et al. 1991, VII/155) from HyperLeda
31- 34 F4.1 deg Inc [12.8/69.4] Inclination from HyperLeda
36- 40 F5.2 Mpc Dist [7.11/22.7] Distance
42 I1 --- r_Dist [1/6] Reference for Dist (1)
44- 46 F3.1 kpc FOV [1.8/5.6] Linear scale of field of view
48- 49 I2 pc Res [9/29] Linear resolution
51- 63 A13 --- Type AGN type
65 A1 --- r_Type Reference for AGN Type (2)
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Note (1): References for distances as follows:
1 = Tully 1988 (Nearby Galaxy Catalog; Cat. VII/145);
2 = Tully et al. 2009AJ....138..323T 2009AJ....138..323T
3 = Terry et al. 2002, Cat. J/A+A/393/57
4 = Rizzi et al. 2007ApJ...661..815R 2007ApJ...661..815R
5 = Ngeow & Kanbur 2006ApJ...642L..29N 2006ApJ...642L..29N
6 = Saha et al. 2006ApJS..165..108S 2006ApJS..165..108S
Note (2): AGN type reference as follows:
a = from Ho et al. (1997, Cat. J/ApJS/112/315);
b = from NED.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Galaxy identifier (NGCNNNN)
9- 11 I3 --- Seq [1/338] H II region identifier
13- 14 I2 h RAh Hour of the Right Ascension (J2000)
16- 17 I2 min RAm Minute of the Right Ascension (J2000)
19- 22 F4.1 s RAs Second of the Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 34 F4.1 arcsec DEs Arcsecond of Declination (J2000)
36- 40 F5.2 [10-7W] logL [36/39.7] Log region Paα luminosity;
erg/s (1)
42- 46 F5.1 pc Diam [16.8/321] Equivalent diameter (2)
48- 51 F4.1 --- S/N [3/69.4] Region signal-to-noise ratio
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Note (1): Uncertainties on logL can be estimated as explained
in the text (Section 2.3).
Note (2): Which matches the area of a circle πD2/4 to that of the region.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 30-Jan-2015