Chandra Observations of the Interacting Galaxies NGC 3395/3396 (Arp 270)

Abstract

In this paper we present the results of a 20 ks high resolution Chandra X-ray observation of the peculiar galaxy pair NGC 3395/3396, a system at a very early stage of merging, and less evolved than the famous Antennae and Mice merging systems. Previously unpublished ROSAT HRI data are also presented. The point source population and the hot diffuse gas in this system are investigated, and compared with other merging galaxy pairs. 16 X-ray point sources are detected in Arp 270, 7 of which are classified as ULXs (Lx > 10^39 erg/s). From spectral fits and the age of the system it seems likely that these are predominantly high mass X-ray binaries. The diffuse gas emits at a global temperature of ~0.5 keV, consistent with temperatures observed in other interacting systems, and we see no evidence of the starburst-driven hot gaseous outflows seen in more evolved systems such as The Mice and The Antennae. It is likely that these features are absent from Arp 270 as the gas has had insufficient time to break out of the galaxy disks. 32% of the luminosity of Arp 270 arises from the diffuse gas in the system, this is low when compared to later stage merging systems and gives further credence that this is an early stage merger. Comparing the ULX population of Arp 270 to other merging systems, we derive a relationship between the star formation rate of the system, indicated by Lfir, and the number (N(ULX)) and luminosity (Lulx) of its ULX population. We find Nulx proportional to Lfir^0.18 and Lulx proportional to Lfir^0.54. These relationships, coupled with the relation of the point source X-ray luminosity (Lxp) to Lk and Lfir+uv (Colbert et al. 2003), indicate that the ULX sources in an interacting system have contributions from both the old and young stellar populations.

arXiv comment18 pages, 16 figures, accepted for publication in MNRAS

References in corpus (33)

• High Mass X-ray Binaries as a Star Formation Rate Indicator in Distant Galaxies
• Theoretical Black Hole Mass Distributions
• Correlated X-ray Spectral and Timing Behavior of the Black Hole Candidate XTE J1550-564: A New Interpretation of Black Hole States
• First Results from the X-ray and Optical Survey of the Chandra Deep Field South
• Chandra X-Ray Observatory (CXO):Overview
• Starburst-driven galactic winds: I. Energetics and intrinsic X-ray emission
• The Ultra-Luminous X-ray Source Population from the Chandra Archive of Galaxies
• Neutron Star Population Dynamics.II: 3D Space Velocities of Young Pulsars
• Chandra High-Resolution Camera Observations of the Luminous X-Ray Source in the Starburst Galaxy M82
• Chandra Observations of "The Antennae" Galaxies (NGC 4038/39)
• Old and Young X-ray Point Source Populations in Nearby Galaxies
• Chandra observations of NGC 253: New insights into the nature of starburst-driven superwinds
• An Empirical Calibration of Star Formation Rate Estimators
• Chandra Observations of the Luminous IR Galaxy NGC3256
• X-Ray Spectral Analysis of Elliptical Galaxies from ASCA: the Fe Abundance in a Multi-Phase Medium
• The optical counterpart of an Ultra-luminous X-Ray Source in NGC 5204
• The star-forming environment of a ULX in NGC 4559: an optical study
• The infrared supernova rate in starburst galaxies
• Displacement of X-Ray Sources from Star Clusters in Starburst Galaxies
• Properties of discrete X-ray sources in the starburst spiral galaxy M83
• A Chandra observation of the interacting pair of galaxies NGC 4485/NGC 4490
• The X-ray Evolution of Merging Galaxies
• A transition to a low/soft state in the ultra-luminous compact X-ray source Holmberg II X-1
• The Time-Variable Ultra-Luminous X-ray Sources of "The Antennae"
• Chandra X-Ray Imaging of the Interacting Starburst Galaxy System NGC 7714/5: Tidal ULXs, Emergent Wind, and Resolved HII Regions
• A thorough study of the intriguing X-ray emission from the Cartwheel ring
• X-ray Source Population in the Elliptical Galaxy NGC 720 with Chandra
• NGC 3256: Kinematic anatomy of a merger
• ROSAT PSPC observations of nearby spiral galaxies - II. Statistical properties
• New Observations of Extra-Disk Molecular Gas in Interacting Galaxy Systems, Including a Two-Component System in Stephan's Quintet
• Chandra Observations of the Mice
• A variable ultra-luminous X-ray source in the colliding galaxy NGC 7714
• BVRI Surface Photometry of (S+S) Binary Galaxies. I. The data

Cited by in corpus (11)

• Ultra-luminous X-ray sources and remnants of massive metal-poor stars
• Low metallicity and ultra-luminous X-ray sources in the Cartwheel galaxy
• The Chandra View of Galaxy Mergers
• ChAInGeS: The Chandra Arp Interacting Galaxies Survey
• Diffuse X-ray-emitting Gas in Major Mergers
• Kinematics of Arp 270: gas flows, nuclear activity and two regimes of star formation
• The Local Environment of Ultraluminous X-ray Sources Viewed by XMM Newton's Optical Monitor
• The Cartwheel galaxy with XMM-Newton
• Outer regions of the merging system Arp 270
• XMM-Newton view of galaxy pairs: activation of quiescent black holes?
• Multiwavelength study of the bright X-ray source population in the interacting galaxies NGC5774/NGC5775