2005A&A...431..451V


C.D.S. - SIMBAD4 rel 1.7 - 2021.03.03CET04:29:49

2005A&A...431..451V - Astronomy and Astrophysics, volume 431, 451-464 (2005/2-4)

Numerical simulations of expanding supershells in dwarf irregular galaxies. II. Formation of giant HI rings.

VOROBYOV E.I. and BASU S.

Abstract (from CDS):

We perform numerical hydrodynamic modeling of various physical processes that can form an HI ring as is observed in Holmberg I (Ho I). Three energetic mechanisms are considered: multiple supernova explosions (SNe), a hypernova explosion associated with a gamma ray burst (GRB), and the vertical impact of a high velocity cloud (HVC). The total released energy has an upper limit of ∼1054erg. We find that multiple SNe are in general more effective in producing shells that break out of the disk than a hypernova explosion of the same total energy. As a consequence, multiple SNe form rings with a high ring-to-center contrast K≲100 in the HI column density, whereas single hypernova explosions form rings with K≲10. Only multiple SNe can reproduce both the size (diameter ∼1.7kpc) and the ring-to-center contrast (K∼15-20) of the HI ring in Ho I. High velocity clouds create HI rings that are much smaller in size (≲0.8kpc) and contrast (K≲4.5) than seen in Ho I. We construct model position-velocity (pV) diagrams and find that they can be used to distinguish among different HI ring formation mechanisms. The observed pV-diagrams of Ho I (Ott et al., 2001AJ....122.3070O) are best reproduced by multiple SNe. We conclude that the giant HI ring in Ho I is most probably formed by multiple SNe. We also find that the appearance of the SNe-driven shell in the integrated HI image depends on the inclination angle of the galaxy. In nearly face-on galaxies, the integrated HI image shows a ring of roughly constant HI column density surrounding a deep central depression, whereas in considerably inclined galaxies (i>45°) the HI image is characterized by two kidney-shaped density enhancements and a mild central depression.

Abstract Copyright:

Journal keyword(s): galaxies: dwarf - ISM: bubbles

Simbad objects: 9

goto Full paper

goto View the reference in ADS

Number of rows : 9

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME Heart Nebula HII 02 32.7 +61 27           ~ 287 1
2 NAME Per Arm PoG 03 30 +45.0           ~ 1290 0
3 UGC 3974 G 07 41 56.3061361330 +16 48 07.439323443   15.4       ~ 206 0
4 [WB2001] 13 HI 07 41 58.9 +16 47 21           ~ 2 0
5 [PWB92] 21 sh 08 19 04 +70 41.3   17.51 17.35     ~ 6 0
6 UGC 4305 IG 08 19 04.9878269182 +70 43 13.025604473 12.06 11.72 11.39 11.11   ~ 706 2
7 UGC 5139 LSB 09 40 32.33 +71 10 56.0 14.53 14.00 13.66 13.41   ~ 327 1
8 M 81 Sy2 09 55 33.17306143 +69 03 55.0609270   7.89 6.94     ~ 4042 5
9 NAME Sex A H2G 10 11 00.5 -04 41 30 12.48 12.13 11.93 11.78   ~ 661 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2005A&A...431..451V and select 'bookmark this link' or equivalent in the popup menu


2021.03.03-04:29:49

© Université de Strasbourg/CNRS

    • Contact