2001A&A...377..759L


Query : 2001A&A...377..759L

2001A&A...377..759L - Astronomy and Astrophysics, volume 377, 759-777 (2001/10-3)

NGC 5775: Anatomy of a disk-halo interface.

LEE S.-W., IRWIN J.A., DETTMAR R.-J., CUNNINGHAM C.T., GOLLA G. and WANG Q.D.

Abstract (from CDS):

We present the first high-resolution study of the disk-halo interface in an edge-on galaxy (NGC 5775) in which every component of the interstellar medium is represented and resolved (though not all to the same resolution). New single-dish CO J=2-1 and CO J=1-0 data, ROSAT X-ray data, and HIRES IRAS data are presented along with HI data which emphasizes the high latitude features. In conjunction with previously published radio continuum (6 and 20 cm) and Hα data, we find spatial correlations between various ISM components in that all components of the ISM are present in the disk-halo features (except for CO for which there is insufficient spatial coverage). The HI features extend to ∼7kpc above the plane, form loops in position-position space, in one case, form a loop in position-velocity space, and are also observed over a large velocity range. This implies that the disk-halo features represent expanding supershells. However, the shells may be incomplete and partially open-topped, suggesting that we are observing the breakup of the supershells as they traverse the disk-halo interface. There is some evidence for acceleration with z and both redshifted and blueshifted velocities are present, although the gas which is lagging with respect to galactic rotation dominates. The radio continuum spectral index is flatter around the shell rims and we show that this cannot be due to a contribution from thermal gas but rather is due to intrinsic flattening of the non-thermal spectral index, suggesting that shocks may be important in these regions. The Hα emission is located interior to the HI. For feature F3, the Hα emission forms the interior ``skin'' of the HI shell, yet there appears to be a minimum of in-disk star formation immediately below the feature. We present a picture of a ``typical'' HI supershell which accelerates and breaks up through the disk-halo interface. Such a feature is likely internally generated via an energetic event in the disk.

Abstract Copyright:

Journal keyword(s): ISM: bubbles - ISM: general - ISM: structure - galaxies: general - galaxies: individual: NGC 5775 - galaxies: spiral

Nomenclature: Fig.1, Table 1: [L98] FN (Nos F1-F3). Fig.7: [LED2001] A (Nos A-C).

CDS comments: Fig.1, Table 1: HI extensions have been catalogued by Lee in his Thesis (1998).

Simbad objects: 14

goto Full paper

goto View the references in ADS

Number of rows : 14
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 NGC 253 SyG 00 47 33.134 -25 17 19.68   8.03   6.94 8.1 ~ 3148 2
2 NGC 891 H2G 02 22 32.907 +42 20 53.95 11.08 10.81 9.93 7.86   ~ 1595 2
3 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5616 6
4 NGC 3079 Sy2 10 01 57.8789863992 +55 40 47.449758324 11.57 11.54 10.86     ~ 1320 3
5 NGC 4631 GiP 12 42 08.009 +32 32 29.44   9.78 9.19 9.10   ~ 1033 2
6 NGC 5774 GiP 14 53 42.46224 +03 34 56.9532   13.9 12.94     ~ 147 1
7 IC 1070 GiP 14 53 51.2833163568 +03 29 04.665529824   15.4       ~ 22 0
8 [LED2001] C PoG 14 53 54.5 +03 33 49           ~ 1 0
9 [LED2001] B PoG 14 53 57.6 +03 32 34           ~ 1 0
10 NGC 5775 GiP 14 53 57.653 +03 32 40.10   13.0 11.34     ~ 416 2
11 [LED2001] A PoG 14 54 01.1 +03 31 26           ~ 1 0
12 [L98] F3 HI ~ ~           ~ 3 0
13 [L98] F2 HI ~ ~           ~ 3 0
14 [L98] F1 HI ~ ~           ~ 3 0

To bookmark this query, right click on this link: simbad:objects in 2001A&A...377..759L and select 'bookmark this link' or equivalent in the popup menu


2022.08.08-04:02:59

© Université de Strasbourg/CNRS

    • Contact