2024ApJ...962...48J


Query : 2024ApJ...962...48J

2024ApJ...962...48J - Astrophys. J., 962, 48 (2024/February-2)

Thermal Properties of the Hot Core Population in Sagittarius B2 Deep South.

JEFF D., GINSBURG A., BULATEK A., BUDAIEV N., SANCHEZ-MONGE A., BONFAND M., BATTERSBY C., MENG F., SCHILKE P. and SCHMIEDEKE A.

Abstract (from CDS):

We report the discovery of nine new hot molecular cores in the Deep South (DS) region of Sagittarius B2 using Atacama Large Millimeter/submillimeter Array Band 6 observations. We measure the rotational temperature of CH3OH and derive the physical conditions present within these cores and the hot core Sgr B2(S). The cores show heterogeneous temperature structure, with peak temperatures between 252 and 662 K. We find that the cores span a range of masses (203-4842 M⊙) and radii (3587-9436 au). CH3OH abundances consistently increase with temperature across the sample. Our measurements show the DS hot cores are structurally similar to Galactic disk hot cores, with radii and temperature gradients that are comparable to sources in the disk. They also show shallower density gradients than disk hot cores, which may arise from the Central Molecular Zone's higher density threshold for star formation. The hot cores have properties which are consistent with those of Sgr B2(N), with three associated with Class II CH3OH masers and one associated with an ultra-compact H IIregion. Our sample nearly doubles the high-mass star-forming gas mass near Sgr B2(S) and suggests the region may be a younger, comparably massive counterpart to Sgr B2(N) and (M). The relationship between peak CH3OH abundance and rotational temperature traced by our sample and a selection of comparable hot cores is qualitatively consistent with predictions from chemical modeling. However, we observe constant peak abundances at higher temperatures (T ≳ 250 K), which may indicate mechanisms for methanol survival that are not yet accounted for in models.

Abstract Copyright: © 2024. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Protoclusters - Chemical abundances - Astrochemistry - Galactic center - Star forming regions - Star formation - Young stellar objects - Protostars

Simbad objects: 18

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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 - 2026
#notes
1 NAME Orion-KL SFR 05 35 14.16 -05 22 21.5           ~ 2421 1
2 JCMTSF J061724.0+145444 Cl* 06 17 24.30 +14 54 37.2           ~ 31 0
3 [BMG2016] Sgr B2(N3) cor 14 47 19.248 -28 22 14.91           ~ 28 0
4 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 16269 0
5 NAME Sgr A* X 17 45 40.03599 -29 00 28.1699           ~ 4970 3
6 NAME Sgr B2 Maser G Mas 17 47 19.397 -28 23 49.77           ~ 4 0
7 [BMG2016] Sgr B2(N4) cor 17 47 19.528 -28 22 32.41           ~ 22 0
8 [QSR2011] Sgr B2(N)-SMA2 cor 17 47 19.885 -28 22 13.29           ~ 114 0
9 [BMG2016] Sgr B2(N1) cor 17 47 19.889 -28 22 18.22           ~ 70 0
10 [BMG2016] Sgr B2(N5) cor 17 47 20.047 -28 22 41.34           ~ 25 0
11 OH 000.657-00.040 Mas 17 47 20.05 -28 23 46.5           ~ 15 0
12 NAME Sgr B2 (North) Rad 17 47 20.2 -28 22 21           ~ 742 1
13 NAME Sgr B2 MoC 17 47 20.4 -28 23 07           ~ 2443 1
14 NAME Sgr B2 (South) HII 17 47 20.430 -28 23 45.06           ~ 106 0
15 NAME Sgr B2 Main Rad 17 47 20.5 -28 23 06           ~ 436 1
16 [SSM2016] Sgr B2(deepS) IR 17 47 20.632 -28 25 30.87           ~ 8 0
17 W 51e2 Ma* 19 23 43.906 +14 30 34.48           ~ 222 0
18 W 51 SNR 19 23 50 +14 06.0           ~ 1352 1

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