1998/12/12 by D. Tsch"oke, Tsch"oke, D., G. Hensler +3
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9812245
13 pages, 12 ps-figures, LATEX-file; accepted for publication in Astron.Astrophys
arxiv created 1998/12/12 · openalex publication_date 1998/12/12 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
We present X-ray observations of the interacting pair of galaxies NGC 4410a/b with the ROSAT HRI and PSPC. The ROSAT HRI images reveal a point-like source corresponding to NGC 4410a and an X-ray halo, extending 10" from the nucleus toward the southeast. The halo emission accounts for ~1/3 (LX=1.3x1041 erg s-1 in the 0.1 - 2.4 keV ROSAT band) of the total X-ray emission detected from NGC 4410a. The spectrum of the total X-ray emission from NGC 4410a can be fitted at best with a two-component emission model, combining a Raymond-Smith spectrum with T = 107 K and a power-law spectrum (Gamma = 2.2). The fraction of the thermal component to the total flux within this model is 35%, supporting the results of the HRI observation. The total unresolved X-ray luminosity detected with the PSPC amounts to 4x1041 erg s-1 in the ROSAT PSPC band (for D = 97 Mpc). A preferable explanation might be the interaction between the two galaxies causing a circumnuclear starburst around the active nucleus in the peculiar late type Sab galaxy NGC 4410a. As a cumulative effect of exploding stars a superbubble forms a bipolar outflow from the galactic disk with an expansion time of ~8 Myr. The central source injects mechanical energy at a constant rate of a few times 1042 erg s-1 into the superbubble. A HST WFPC2 image decovers that NGC 4410a is seen almost face-on so that only the approaching outflow is visible. The HRI contours reveal an elongation of this outflow indicative for a faint X-ray ridge below the detection limit (LX <= 1.4x1039 erg s-1) toward the neighbouring galaxy NGC 4410b caused by its tidal interaction. NGC 4410b houses only a faint X-ray source (LX <= 3.8x1039 erg s-1).