Sasmirala Individual Information for ESO 500-34
Description
ESO 500-34 is a spiral galaxy at a redshift of z = 0.0122 (D ~ 55.6 Mpc) with an active nucleus containing a starburst and possibly an AGN [hill_starburst_1999]. It is optically classified either as a Sy 2 or an H II [yuan_role_2010], and we treat it as uncertain AGN/starburst composite. There is no evidence for the presence of an AGN available at X-ray or radio wavelengths. No Spitzer observations are available, and it appears as an elongated source along the host galaxy major axis, in particular in the short-wavelength WISE bands. ESO 500-34 has only been imaged once with VISIR in 2005 in one narrow N-band filter [siebenmorgen_nuclear_2008]. An elongated extended emission source without any clear nuclear component was detected. The major axis is roughly in the north-south directions (~ 3arcsec ~ 800 pc) with the emission peak on the northern side. Because no AGN component can be identified, [siebenmorgen_nuclear_2008] conclude that the primary MIR emission source is star formation. We use the unresolved flux in the emission peak position to estimate an upper limit on any AGN in ESO 500-34. MIR spectroscopy and further imaging will be necessary to decide on the nature of the MIR emission in this object.
- [hill_starburst_1999] Tanya L. Hill, Charlene A. Heisler, Ralph Sutherland, and Richard W. Hunstead. Starburst or seyfert? using near-infrared spectroscopy to measure the activity in composite galaxies . AJ , 117 pp. 111–125, January 1999.
- [siebenmorgen_nuclear_2008] R. Siebenmorgen, M. Haas, E. Pantin, E. Krügel, C. Leipski, H. U. Käufl, P. O. Lagage, A. Moorwood, A. Smette, and M. Sterzik. Nuclear activity in nearby galaxies. mid-infrared imaging with the VLT . A&A , 488 pp. 83–90, September 2008.
- [yuan_role_2010] T.-T. Yuan, L. J. Kewley, and D. B. Sanders. The role of starburst-active galactic nucleus composites in luminous infrared galaxy mergers: Insights from the new optical classification scheme . ApJ , 709 pp. 884–911, February 2010.
Images
Optical image (DSS, red filter). Displayed are the central 4 arcmin with North being up and East to the left. The colour scaling is linear with white corresponding to the median background (BG) and black to the 0.01% pixels with the highest intensity.
Subarcsecond-resolution MIR images sorted by increasing filter central wavelength. Displayed are the inner 4 arcsec with North being up and East to the left. The colour scaling is logarithmic with white corresponding to median BG and black to the 75% of the highest intensity of all images in units of sig_bg. The inset image (where present; either bottom or top right) shows the central arcsecond of the PSF from the calibrator star, scaled to match the science target. The labels in the bottom left state instrument and filter names (C: COMICS, M: Michelle, T: T-ReCS, V: VISIR).
SEDs
MIR SED. The description of the symbols in all the SED plots (where present) is the following: Grey crosses and solid lines mark the Spitzer/IRAC, MIPS and IRS data. The colour coding of the other symbols is as follows: green for COMICS, magenta for Michelle, blue for T-ReCS and red for VISIR data. Darker-coloured solid lines mark spectra of the corresponding instrument. The black filled circles mark the nuclear 12 and 18 micron continuum emission estimate from the data (where present). The ticks on the top axis mark positions of common MIR emission lines, while the light grey horizontal bars mark wavelength ranges affected by the silicate 10 and 18 micron features.