2023A&A...671A.104C


Query : 2023A&A...671A.104C

2023A&A...671A.104C - Astronomy and Astrophysics, volume 671A, 104 (2023/3-1)

Exploring extreme conditions for star formation: A deep search for molecular gas in the Leo ring.

CORBELLI E., THILKER D., MANNUCCI F. and CRESCI G.

Abstract (from CDS):

Aims. We carried out sensitive searches for the 12CO J = 1-0 and J = 2-1 lines in the giant extragalactic HI ring in Leo to investigate the star formation process within environments where gas metallicities are close to solar, but physical conditions are different than those typical of bright galaxy disks. Our aim is to check the range of validity of known scaling relations.
Methods. We used the IRAM-30 m telescope to observe 11 regions close to HI gas peaks or where sparse young massive stars have been found. For all pointed observations we reached spectral noise between 1 and 5 mK for at least one of the observed frequencies at 2 km s–1 spectral resolution.
Results. We marginally detect two 12CO J = 1-0 lines in the star-forming region Clump 1 of the Leo ring, whose radial velocities are consistent with those of Hα lines, but whose line widths are much smaller than observed for virialized molecular clouds of similar mass in galaxies. The low signal-to-noise ratio, the small line widths, and the extremely low number densities inferred by virialized cloud models suggest that a more standard population of molecular clouds, still undetected, might be in place. Using upper limits to the CO lines, the most sensitive pointed observations show that the molecular gas mass surface density is lower than expected from the extrapolation of the molecular Kennicutt-Schmidt relation established in the disk of galaxies. The sparse stellar population in the ring, possibly forming ultra diffuse dwarf galaxies, might then be the result of a short molecular gas depletion time in this extreme environment.

Abstract Copyright: © The Authors 2023

Journal keyword(s): galaxies: star formation - galaxies: dwarf - ISM: molecules - submillimeter: ISM - HII regions - galaxies: interactions

Status at CDS : Examining the need for a new acronym.

Simbad objects: 18

goto Full paper

goto View the references in ADS

Number of rows : 18
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 M 33 GiG 01 33 50.8965749232 +30 39 36.630403128 6.17 6.27 5.72     ~ 5847 1
2 M 74 G 01 36 41.7451236624 +15 47 01.107512304 10.52 10.00 9.46 9.16   ~ 1741 1
3 [SST86] 1 HI 10 47 46.8 +12 11 11           ~ 7 0
4 [CCM2021] C1b HII 10 47 47.44 +12 11 27.6           ~ 3 0
5 [CCM2021] C1a HII 10 47 47.93 +12 11 31.9           ~ 3 0
6 M 105 LIN 10 47 49.600 +12 34 53.87   10.56 9.76 9.12 8.18 ~ 1464 0
7 [SST86] 2 HI 10 47 54.9 +12 14 13           ~ 6 0
8 NAME M96 Group GrG 10 48 +13.3           ~ 315 0
9 [CCM2021] C2Ea HII 10 48 13.52 +12 02 24.3           ~ 3 0
10 [SST86] 2E HI 10 48 14.0 +12 02 27           ~ 5 0
11 [CCM2021] C2Eb HII 10 48 14.08 +12 02 32.5           ~ 3 0
12 [CCM2021] C2Ef HII 10 48 14.48 +12 02 20.1           ~ 2 0
13 NGC 3384 GiG 10 48 16.8855574392 +12 37 45.371165844   10.0       ~ 596 1
14 NGC 5068 AG? 13 18 54.807 -21 02 20.76 11.24 10.53 10.01 9.78 10.1 ~ 292 0
15 M 51 Sy2 13 29 52.698 +47 11 42.93   9.26 8.36 8.40   ~ 4333 4
16 M 83 SBG 13 37 00.91920 -29 51 56.7400 8.85 8.11 7.52 7.21   ~ 2580 2
17 NAME Leo Ring HI ~ ~           ~ 59 0
18 NAME Leo Cloud Cld ~ ~           ~ 61 0

To bookmark this query, right click on this link: simbad:objects in 2023A&A...671A.104C and select 'bookmark this link' or equivalent in the popup menu