Radio Detection of Supernova 2004ip in the Circumnuclear Region of the Luminous Infrared Galaxy IRAS 18293-3413

Monthly Notices of the Royal Astronomical Society

Kniazev

et al. 2008

Self Cite

We present near‐infrared (NIR) adaptive optics imaging obtained with VLT/NACO and optical spectroscopy from the Southern African Large Telescope of a luminous IR galaxy (LIRG) IRAS 19115−2124. These data are combined with archival Hubble Space Telescope imaging and Spitzer imaging and spectroscopy, allowing us to study this disturbed interacting/merging galaxy, dubbed the Bird, in extraordinary detail. In particular, the data reveal a triple system where the LIRG phenomenon is dominated by the smallest of the components. One nucleus is a regular barred spiral with significant rotation, while another is highly disturbed with a surface brightness distribution intermediate to that of disc and bulge systems, and hints of remaining arm/bar structure. We derive dynamical masses in the range 3–7 × 1010 M⊙ for both. The third component appears to be a 1–2 × 1010 M⊙ mass irregular galaxy. The total system exhibits H ii galaxy‐like optical line ratios and strengths, and no evidence for active galactic nucleus (AGN) activity is found from optical or mid‐IR data. The star formation rate is estimated to be ∼190 M⊙ yr−1. We also report a search for supernovae from NIR images separated by five months and search for superstar cluster candidates. We detect outflowing gas from the Bird mostly in the range 100–300 km s−1 using Na i D absorption features. Overall, the Bird shows kinematic, dynamical and emission‐line properties typical for cool ultraluminous IR galaxies (ULIRGs). However, the interesting features setting it apart for future studies are its triple merger nature, and the location of its star formation peak – the strongest star formation, as revealed by Spitzer imaging, does not come from the two major K‐band nuclei, but from the third irregular component. This is in contrast to the conventional view that the (U)LIRG phases are powered by infalling gas to the major nuclei of the merging spiral galaxies. Aided by simulations, we discuss scenarios where the irregular component is on its first high‐speed encounter with the more massive components.

Section: Discussionmentioning

confidence: 99%

Adaptive optics imaging and optical spectroscopy of a multiple merger in a luminous infrared galaxy^★

Vaïsänen

Monthly Notices of the Royal Astronomical Society

Kniazev

et al. 2008

Self Cite

“…The K-band data set used here was taken on 2004 September 14 with the S27 camera, giving a pixel size of 0.027Љ, and using the visual wave-front sensor. These observations and data reduction are described in more detail in Mattila et al (2007), where we presented the discovery of the highly obscured core collapse (see Pérez-Torres et al 2007) supernova 2004ip detected within the nuclear regions of this galaxy. The final combined Kband image (Fig.…”

Section: Observations and Data Reductionmentioning

confidence: 96%

A Pair of Leading Spiral Arms in a Luminous Infrared Galaxy?

Vaïsänen

Ryder

et al. 2008

ApJ

Leading spiral arms are a rare phenomenon. We present here one of the very few convincing candidates of spiral arms opening counterintuitively in the same direction as the galaxy disk is rotating. This detection in the luminous IR galaxy (LIRG) IRAS 18293Ϫ3413 is based on near-infrared (NIR) adaptive optics imaging with the Very Large Telescope and long-slit NIR spectroscopy with the Anglo-Australian Telescope. We discuss the orientation of the galaxy based on imaging and derive rotation curves from both emission and absorption features in the spectrum. The galaxy is strongly star-forming and has a minor companion in a high-velocity encounter. The fact that the arms of IRAS 18293Ϫ3413 are not easily traceable from optical images suggests that larger samples of high-quality NIR imaging of interacting systems and LIRGs might uncover further cases of leading arms, placing constraints on spiral arm theories and retrogade encounters, and especially on the relationship between disk masses and dark matter halo masses.

“…For example, SN 2004ip with a likely high extinction A V > 5 mag (Mattila et al 2007) was detected at a projected distance of 1.4 arcsec, or 500 pc, from the K ‐band nucleus of the nearby LIRG, IRAS 18293−3413. Its core‐collapse nature was confirmed by a Very Large Array (VLA) detection at 8.4 GHz (Pérez‐Torres et al 2007). Two circumnuclear SNe, SN 2004iq and SN 2008cs (Kankare et al 2008) were detected in the circumnuclear regions of the nearby LIRG IRAS 17138−1017.…”

Section: Introductionmentioning

confidence: 93%

The core-collapse supernova rate in Arp 299 revisited

Romero-Cañizales

Monthly Notices of the Royal Astronomical Society

Alberdi

et al. 2011

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We present a study of the core‐collapse supernova (CCSN) rate in nuclei A and B1, of the luminous infrared galaxy (LIRG) Arp 299, based on ∼11 yr of Very Large Array (VLA) monitoring of their radio emission at 8.4 GHz. Significant variations in the nuclear radio flux density can be used to identify the CCSN activity in the absence of high‐resolution very long baseline interferometry (VLBI) observations. In the case of the B1‐nucleus, the small variations in its measured diffuse (synchrotron plus free–free) radio emission are below the fluxes expected from radio supernovae (RSNe), thus making it well‐suited to detect RSNe through flux density variability. In fact, we find strong evidence for at least three RSNe this way, which results in a lower limit for the CCSN rate (νSN) of >0.28+0.27−0.15 yr−1. This value agrees within the uncertainties with the infrared (IR) luminosity based SN rate estimate, and with previously reported radio estimates. In the A‐nucleus, we did not detect any significant variability and found a SN detection threshold luminosity of ≈3.1 × 1028 erg s−1 Hz−1, allowing only the detection of the most luminous RSNe known. Our method is basically blind to normal CCSN explosions occurring within the A‐nucleus, which result in too small variations in the nuclear flux density, remaining diluted by the strong diffuse emission of the nucleus itself. Additionally, we have attempted to find near‐IR (NIR) counterparts for the earlier reported RSNe in the Arp 299 nucleus A, by comparing NIR adaptive optics images from the Gemini‐N Telescope with contemporaneous observations from the European VLBI Network (EVN). However, we were not able to detect NIR counterparts for the reported radio SNe within the innermost regions of nucleus A. While our NIR observations were sensitive to typical CCSNe at ∼300 mas (or 70 pc projected distance) from the centre of the nucleus A, suffering from extinction up to AV∼ 15 mag, they were not sensitive to such highly obscured SNe within the innermost nuclear regions where most of the EVN sources were detected.