The Nearby Dwarf Irregular Galaxy IC 1613 and Its Complex Bubble Region: Chandra and VLA Observations

Abstract

Abstract We observed the nearby irregular galaxy IC 1613 with the Chandra X-ray Observatory, for 49.9 ks using the ACIS S3 chip, and with the VLA at 6 cm for 0.7 hr. The Chandra observation targeted the extensive bubble region in the northeast quadrant. We detect 31 sources within the D 25 diameter above a significance of 3σ corresponding to a point-source luminosity limit L X of ≈2 × 1035 erg s−1 (0.3–8 keV band). The VLA observation covered the entire galaxy with an angular resolution of 5″. We detect 11 sources: five do not fall on the ACIS chips, four fall on the S3 CCD, and two sit on the edge of the S2 CCD. We also describe corresponding Spitzer IRAC and MIPS images. Our detected source list matches the lists of two previous global point-source analyses except at the faint end. With the exception of one bright supernova remnant, the sources appear to be low-luminosity stellar sources (e.g., RS CVn stars) or X-ray binaries, or background objects. We identify one candidate supersoft source. All but one of the sources have at least one optical or infrared counterpart; three sources have radio counterparts. We describe our search for diffuse emission from the bubble region. We assign an upper limit of ≈5 × 1035 erg s−1 on the integrated flux and ≈1.4 × 1030 erg s−1 pc−2 on the surface brightness emission in the 0.5–2 keV band from that region.