Sasmirala Individual Information for NGC 676
Description
NGC 676 is an edge-on spiral galaxy at a distance of D = 19.5 ± 8.7 Mpc [tully_nearby_1988] with a Sy 2 nucleus [veron-cetty_catalogue_2010], which is undetected at radio wavelengths [ho_detection_2001]. No Spitzer observations are available for NGC 676. In the WISE images, it appears elliptically elongated along the galaxy major axis. We observed NGC 676 with VISIR in PAH2 and NEII_1 in 2009 and in PAH2 and PAH2_2 in 2010 [asmus_mid-infrared_2011] but the nucleus remained undetected in all cases. The foreground star 5arcsecsouth of the galaxy centres allows us to derive an accurate upper limit for the nuclear emission in NGC 676. This non-detection does not exclude the presence of an AGN because the upper limit on the flux is consistent with the one expected from the MIR–X-ray luminosity correlation (see [asmus_mid-infrared_2011]).
- [asmus_mid-infrared_2011] D. Asmus, P. Gandhi, A. Smette, S. F. Hönig, and W. J. Duschl. Mid-infrared properties of nearby low-luminosity AGN at high angular resolution . A&A , 536 pp. 36, December 2011.
- [ho_detection_2001] Luis C. Ho, Eric D. Feigelson, Leisa K. Townsley, Rita M. Sambruna, Gordon P. Garmire, W. N. Brandt, Alexei V. Filippenko, Richard E. Griffiths, Andrew F. Ptak, and Wallace L. W. Sargent. Detection of nuclear x-ray sources in nearby galaxies with chandra . ApJ , 549 pp. L51–L54, March 2001.
- [tully_nearby_1988] R. Brent Tully. Nearby galaxies catalog . Cambridge University Press, 1988.
- [veron-cetty_catalogue_2010] M.-P. Véron-Cetty and P. Véron. A catalogue of quasars and active nuclei: 13th edition . A&A , 518 pp. 10, July 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.
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.