J/MNRAS/451/1307 HII regions in 10 galaxies (Zaragoza-Cardiel+, 2015)
Comparative internal kinematics of the HII regions in interacting and isolated
galaxies: implications for massive star formation modes.
Zaragoza-Cardiel J., Beckman J.E., Font J., Garcia-Lorenzo B.,
Camps-Farina A., Fathi K., James P.A., Erroz-Ferrer S.,
Barrera-Ballesteros J., Cisternas M.
<Mon. Not. R. Astron. Soc. 451, 1307 (2015)>
=2015MNRAS.451.1307Z 2015MNRAS.451.1307Z
ADC_Keywords: Galaxies, nearby ; H II regions
Keywords: stars: formation - HII regions - galaxies: interactions -
galaxies: kinematics and dynamics - galaxies: starburst
Abstract:
We have observed 10 interacting galaxy pairs using the Fabry-Perot
interferometer GHαFaS (Galaxy Hα Fabry-Perot system) on
the 4.2m William Herschel Telescope (WHT) at the Observatorio del
Roque de los Muchachos, La Palma. We present here the Hα surface
brightness, velocity and velocity dispersion maps for the 10 systems
we have not previously observed using this technique, as well as the
physical properties (sizes, Hα luminosities and velocity
dispersion) of 1259 HII regions from the full sample. We also derive
the physical properties of 1054 HII regions in a sample of 28 isolated
galaxies observed with the same instrument in order to compare the two
populations of HII regions. We find a population of the brightest HII
regions for which the scaling relations, for example the relation
between the Hα luminosity and the radius, are clearly distinct
from the relations for the regions of lower luminosity. The regions in
this bright population are more frequent in the interacting galaxies.
We find that the turbulence, and also the star formation rate, are
enhanced in the HII regions in the interacting galaxies. We have also
extracted the Hα equivalent widths for the HII regions of both
samples, and we have found that the distribution of HII region ages
coincides for the two samples of galaxies. We suggest that the SFR
enhancement is brought about by gas flows induced by the interactions,
which give rise to gravitationally bound gas clouds which grow further
by accretion from the flowing gas, producing conditions favourable to
star formation.
Description:
We observed the interacting galaxies with GHαFaS, a
Fabry-Perot interferometer mounted on the WHT (William Herschel
Telescope) at the Roque de los Muchachos Observatory, La Palma.
Objects:
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RA (2000) DE Designation(s)
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01 24 35.1 +03 47 33 NGC 520 = LEDA 5193
06 18 37.7 +78 21 25 NGC 2146 = UGC 3429
07 44 09.3 +29 14 48 UGC 3995 = LEDA 21673
09 14 05.1 +40 06 49 NGC 2782 = LEDA 26034
09 45 42.0 -14 19 35 NGC 2992 = LEDA 27982
09 45 48.3 -14 22 06 NGC 2993 = LEDA 27991
11 37 44.1 +47 53 35 NGC 3769 = UGC 6595
11 39 42.5 +31 54 33 NGC 3786 = LEDA 36158
11 39 44.6 +31 55 52 NGC 3788 = LEDA 36160
11 57 31.1 +32 20 16 NGC 3991 = UGC 6933
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 118 1256 Physical properties of the brightest HII regions
in interacting galaxies
tablea2.dat 118 1043 Physical properties of the brightest HII regions
in isolated galaxies
list.dat 117 36 List of fits files
fits/* . 36 Individual fits files
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See also:
J/A+A/393/389 : Hα in spiral galaxies HII regions (Marquez+, 2002)
J/A+A/481/645 : HII regions in interacting galaxies (Ferreiro+, 2008)
J/other/RAA/14.1393 : HII regions in interacting system Arp 86 (Zhou+, 2014)
Byte-by-byte Description of file: tablea1.dat tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/303] Consecutive number in catalog,
within the galaxy
5- 11 A7 --- Name Galaxy name
13- 14 I2 h RAh Right Ascension (J2000)
16- 17 I2 min RAm Right Ascension (J2000)
19- 22 F4.1 s RAs [0/60] Right Ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs [0/60] Declination (J2000)
36- 41 F6.3 [10-7W] logLHa [35/41] Log of Hα luminosity (erg/s)
43- 47 F5.3 [10-7W] e_logLHa [0.006/0.4] Log of Hα luminosity error
49- 51 I3 pc R [16/481] Globular radius
53- 54 I2 pc e_R [1/50] Radius error
56- 59 F4.2 [Msun] logMHII [3.2/7.6] Ionized gas mass
61- 64 F4.2 [Msun] e_logMHII [0.03/0.9] Ionized gas mass error
66- 71 F6.4 Msun/pc3 rhoHII [0.007/0.37] Ionized gas density ρHII
73- 78 F6.4 Msun/pc3 e_rhoHII [0.0004/0.09] Ionized gas density error
81- 84 F4.1 km/s sigma [4/43] Velocity dispersion σ
86- 89 F4.1 km/s e_sigma [0.3/10]? Velocity dispersion error
91- 97 F7.1 --- alpVir [1/10000]? Virial parameter (αvir) (1)
99-104 F6.1 --- e_alpVir [0.5/7000]? Virial parameter error
106-112 F7.2 0.1nm EWHa [0.03/2033]? Hα equivalent width
114-118 F5.3 [yr] logAge [6.3/7.8]? Log of Age
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Note (1): the virial parameter is:
αvir = 5σ2R / (G Mgas)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix Scale [0.197/0.201] Scale of the image
26- 29 I4 --- Nx [1024] Number of pixels along X-axis
31- 34 I4 --- Ny [1024] Number of pixels along Y-axis
36- 37 I2 --- Nz [48]? Number of slices for datacubes
39- 46 F8.3 km/s V.min [557/4574]? Lower value of velocity interval
for datacubes
48- 55 F8.3 km/s V.max [946/4952]? Upper value of velocity interval
for datacubes
57- 63 F7.5 km/s dV [8/8.3]? Velocity resolution for datacubes
65- 70 I6 Kibyte Size [4103/196619] Size of FITS file
72-117 A46 --- FileName Name of the file, in subdirectory "fits"
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Acknowledgements:
Javier Zaragoza-Cardiel, jzc(at)iac.es
Hsitory:
* 12-Jun-2015: first on-line version
* 12-Dec-2015: first digit of Sequential number of tablea1 restored
* 16-Mar-2017: tables a1 and a2 corrected (from author)
(End) Patricia Vannier [CDS] 12-Jun-2015