TY - JOUR
T1 - Studying the multi-phase interstellar medium in the Large Magellanic Cloud with SRG/eROSITA
T2 - I. analysis of diffuse X-ray emission
AU - Mayer, Martin G. F.
AU - Sasaki, Manami
AU - Haberl, Frank
AU - Tsuge, Kisetsu
AU - Fukui, Yasuo
AU - Maitra, Chandreyee
AU - Filipović, Miroslav D.
AU - Smeaton, Zachary J.
AU - Staveley-Smith, Lister
AU - Koribalski, Bärbel
AU - Points, Sean
AU - Kavanagh, Patrick
PY - 2025/8
Y1 - 2025/8
N2 - Context. The Large Magellanic Cloud (LMC), being a nearby and actively star-forming satellite galaxy of the Milky Way, is an ideal site to observe the multiphase interstellar medium (ISM) of a galaxy across the electromagnetic spectrum. Aims. We aimed to exploit the available SRG/eROSITA all-sky survey data to study the distribution, composition and properties of the diffuse X-ray emitting hot gas in the LMC. Methods. We constructed multiband X-ray images of the LMC, reflecting the morphology and temperatures of the diffuse hot gas. By performing spatially resolved X-ray spectroscopy of 175 independent regions, we constrained the distribution, temperature, mass, energetics and composition of the hot ISM phase throughout the galaxy, while also testing for the presence of X-ray synchrotron emission. We combined our constraints with multiwavelength data to obtain a comprehensive view of the different ISM phases. Results. We measure a total X-ray luminosity of the hot ISM phase of 1.9 × 1038 erg s-1 (0.2-5.0 keV band), and constrain its thermal energy to around 9 × 1054 erg. The typical density and temperature of the X-ray emitting plasma are around 5 × 10-3 cm-3 and 0.25 keV, respectively, with both exhibiting broad peaks in the southeast of the LMC. The observed degree of X-ray absorption correlates strongly with the distribution of foreground H I gas, whereas a spatial anticorrelation between the hot and cold ISM phases is visible on sub-kpc scales within the disk. The abundances of light metals show a strong gradient throughout the LMC, with the north and east exhibiting a strong α-enhancement, as expected from observed massive stellar populations there. In contrast, the enigmatic "X-ray spur"exhibits a local deficit in α-elements, and a peak in hot-gas pressure at P/k ∼ 105 K cm-3, consistent with a dominant energy input through tidally driven gas collisions. Finally, we tentatively identify spectroscopic signatures of nonthermal X-ray emission from the supergiant shell LMC 2, although contamination by straylight cannot be excluded.
AB - Context. The Large Magellanic Cloud (LMC), being a nearby and actively star-forming satellite galaxy of the Milky Way, is an ideal site to observe the multiphase interstellar medium (ISM) of a galaxy across the electromagnetic spectrum. Aims. We aimed to exploit the available SRG/eROSITA all-sky survey data to study the distribution, composition and properties of the diffuse X-ray emitting hot gas in the LMC. Methods. We constructed multiband X-ray images of the LMC, reflecting the morphology and temperatures of the diffuse hot gas. By performing spatially resolved X-ray spectroscopy of 175 independent regions, we constrained the distribution, temperature, mass, energetics and composition of the hot ISM phase throughout the galaxy, while also testing for the presence of X-ray synchrotron emission. We combined our constraints with multiwavelength data to obtain a comprehensive view of the different ISM phases. Results. We measure a total X-ray luminosity of the hot ISM phase of 1.9 × 1038 erg s-1 (0.2-5.0 keV band), and constrain its thermal energy to around 9 × 1054 erg. The typical density and temperature of the X-ray emitting plasma are around 5 × 10-3 cm-3 and 0.25 keV, respectively, with both exhibiting broad peaks in the southeast of the LMC. The observed degree of X-ray absorption correlates strongly with the distribution of foreground H I gas, whereas a spatial anticorrelation between the hot and cold ISM phases is visible on sub-kpc scales within the disk. The abundances of light metals show a strong gradient throughout the LMC, with the north and east exhibiting a strong α-enhancement, as expected from observed massive stellar populations there. In contrast, the enigmatic "X-ray spur"exhibits a local deficit in α-elements, and a peak in hot-gas pressure at P/k ∼ 105 K cm-3, consistent with a dominant energy input through tidally driven gas collisions. Finally, we tentatively identify spectroscopic signatures of nonthermal X-ray emission from the supergiant shell LMC 2, although contamination by straylight cannot be excluded.
KW - ISM: abundances
KW - ISM: structure
KW - X-rays: ISM
UR - http://www.scopus.com/inward/record.url?scp=105013247373&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202554971
DO - 10.1051/0004-6361/202554971
M3 - Article
AN - SCOPUS:105013247373
SN - 0004-6361
VL - 700
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A137
ER -