J/ApJ/862/25 Hα & UV emission scale heights for edge-on gal. (Jo+, 2018)
Comparison of the extraplanar Hα and UV emissions in the halos of nearby
edge-on spiral galaxies.
Jo Y.-S., Seon K.-I., Shinn J.-H., Yang Y., Lee D., Min K.-W.
<Astrophys. J., 862, 25 (2018)>
=2018ApJ...862...25J 2018ApJ...862...25J
ADC_Keywords: Galaxies, nearby; Ultraviolet; Optical; Interstellar medium
Keywords: dust, extinction ; H II regions ; ISM: structure ; line: formation ;
radiative transfer ; scattering
Abstract:
We compare vertical profiles of the extraplanar Hα emission to
those of the UV emission for 38 nearby edge-on late-type galaxies. It
is found that detection of the "diffuse" extraplanar dust (eDust),
traced by the vertically extended, scattered UV starlight, always
coincides with the presence of the extraplanar Hα emission. A
strong correlation between the scale heights of the extraplanar
Hα and UV emissions is also found; the scale height at Hα
is found to be ∼0.74 of the scale height at FUV. Our results may
indicate the multiphase nature of the diffuse ionized gas and dust in
the galactic halos. The existence of eDust in galaxies where the
extraplanar Hα emission is detected suggests that a larger
portion of the extraplanar Hα emission than that predicted in
previous studies may be caused by Hα photons that originate from
HII regions in the galactic plane and are subsequently scattered by
the eDust. This possibility raise an advantage in studying the
extraplanar diffuse ionized gas. We also find that the scale heights
of the extraplanar emissions normalized to the galaxy size correlate
well with the star formation rate surface density of the galaxies. The
properties of eDust in our galaxies is on a continuation line of that
found through previous observations of the extraplanar polycyclic
aromatic hydrocarbons emission in more active galaxies known to have
galactic winds.
Description:
We analyzed the narrowband Hα and UV images of the nearby
late-type edge-on galaxies, which were taken from previous Hα
and UV galaxy surveys (see reference papers in Table 1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 91 38 Galaxy sample
table2.dat 62 38 Scale heights of the sample galaxies
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See also:
VII/109 : IRAS Observations of Large Optical Galaxies (Rice+, 1988)
VII/141 : Spectrophotometric Atlas of Galaxies (Kennicutt Jr. 1992)
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
J/A+A/414/23 : CCD Hα and R photometry of 334 galaxies (James+, 2004)
J/ApJS/165/307 : Survey for ionization in neutral gas gal. I. (Meurer+, 2006)
J/ApJS/178/247 : Hα and [NII] survey in local 11 Mpc (Kennicutt+, 2008)
J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)
J/ApJS/190/233 : Spectroscopy & abundances of SINGS galaxies (Moustakas+, 2010)
J/A+A/545/A16 : Halpha3. Catalog and SFR in Virgo cluster (Gavazzi+, 2012)
http://www.astro.ljmu.ac.uk/HaGS/fits/index.html : HαGS FITS images
http://irsa.ipac.caltech.edu/data/SPITZER/SINGS/ : SINGS Spitzer and Ancillary
data archive on IRSA.
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/38] Running index number
4- 17 A14 --- Name Galaxy name taken from NED
19- 28 A10 --- Morph Galaxy morphology
30- 35 F6.2 deg GLON [10.7/357.8] Galactic longitude
37- 42 F6.2 deg GLAT [-74.6/84.3] Galactic latitude
44- 48 F5.2 pc Dist [4.1/26.9] Average value of the
redshift-independent distances from NED
50- 54 F5.2 arcmin Dmaj [1.3/19.4] Major axis diameter in arcmin
56- 59 F4.1 kpc D25 [3.7/47.3] Major axis diameter in kpc
calculated using col. Dist and Dmag
61- 66 F6.3 10+33W LHa [0.1/11.5]? Integrated Hα luminosity
from reference papers (x1040erg/s)
68- 73 F6.4 Msun/yr SFH-Ha [0.01/1]? Star formation rate based on
the Hα luminosity
75- 80 F6.4 Msun/yr SFH-FIR [0.0009/1.6] Star formation rate estimated
using the FIR luminosity
82- 91 A10 --- Ref Reference papers (1)
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Note (1): Reference papers as follows:
Hα3 = Hα narrow band imaging survey of galaxies,
Gavazzi+ (2003A&A...400..451G 2003A&A...400..451G, 2012, J/A+A/545/A16);
HαGS = Hα Galaxy Survey, James+ (2004, J/A+A/414/23);
LVL = Spitzer Local Volume Legacy, Kennicutt+ (2008, J/ApJS/178/247),
Dale+ (2009, J/ApJ/703/517);
Rossa = Rossa & Dettmar (2003A&A...406..493R 2003A&A...406..493R, 2003A&A...406..505R 2003A&A...406..505R);
SINGG = Survey for Ionization in Neutral Gas Galaxies,
Meurer+ (2006, J/ApJS/165/307);
SINGS = Spitzer Infrared Nearby Galaxies Survey, Kennicutt+
(2003PASP..115..928K 2003PASP..115..928K), Moustakas+ (2010, J/ApJS/190/233).
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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- 2 I2 --- Seq [1/38] Running index number
4- 17 A14 --- Name Galaxy name taken from NED
19- 19 A1 --- Group Group (2)
21- 26 F6.4 Msun/yr SFH-FIR [0.0009/1.6] Star formation rate estimated
using the FIR luminosity
28- 32 F5.3 kpc ZHa [0.1/1.4] Scale height, Hα
34- 38 F5.3 kpc e_ZHa [0.002/0.3] Uncertainty in ZHa
40- 44 F5.3 kpc ZFUV [0.1/2.035] Scale height, FUV
46- 50 F5.3 kpc e_ZFUV [0.004/0.5] Uncertainty in ZFUV
52- 56 F5.3 kpc ZNUV [0.1/2] Scale height, NUV
58- 62 F5.3 kpc e_ZNUV [0.007/0.5] Uncertainty in ZNUV
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Note (2): The sample galaxies were divided into two groups for convenience,
as follows:
A = scale height of less than 0.4kpc in both UV wavelength bands
(17 occurrences);
B = scale height greater than 0.4kpc in both UV bands (21 occurrences).
See section 3.2 for further explanations.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Jul-2019