Sasmirala Individual Information for NGC 613
Description
NGC 613 is a late-type spiral galaxy at a distance of D = 26.6 ± 5.3 Mpc (NED redshift-independent median) with an active nucleus classified as an AGN/starburst composite [veron_agns_1997] and a surrounding elliptical starburst ring (major axis~ 7arcsec ~ 900 pc; PA~ 110∘; [hummel_central_1992]). It shows a complex [O III] and radio morphology, possibly caused by an AGN ([hummel_central_1987]; see also [boker_sinfoni_2008]). In addition, nuclear water maser emission was detected [kondratko_discovery_2006]. After IRAS, NGC 613 was observed with ISO [roussel_atlas_2001] and Spitzer/IRS and MIPS. In the MIPS 24 μm image the nucleus is blended with the elliptical starburst ring. The IRS HR staring-mode spectrum is as well affected by the starburst ring and exhibits strong PAH emission and a red spectral slope in νFν-space (see also [goulding_towards_2009]). NGC 613 was observed with T-ReCS in the N filter in 2010 (unpublished, to our knowledge). In this image, the starburst ring and a compact MIR nucleus are clearly resolved. The nucleus appears possibly marginally resolved (FWHM ~ 0.39arcsec ~ 50 pc) but this is not sufficient to robustly determined the nuclear subarcsecond MIR morphology. The nuclear flux determined by T-ReCS photometry is only 6% of the Spitzer spectrophotometry demonstrating the dominance of the starburst ring in the MIR. The detection of the compact MIR nucleus is another indication for an AGN in NGC 613 in agreement with the results of [goulding_towards_2009].
- [boker_sinfoni_2008] Torsten Böker, Jesús Falcón-Barroso, Eva Schinnerer, Johan H. Knapen, and Stuart Ryder. A SINFONI view of galaxy centers: Morphology and kinematics of five nuclear star formation-rings . AJ , 135 pp. 479–495, February 2008.
- [goulding_towards_2009] A. D. Goulding and D. M. Alexander. Towards a complete census of AGN in nearby galaxies: a large population of optically unidentified AGN . MNRAS , 398 pp. 1165–1193, September 2009.
- [hummel_central_1987] E. Hummel, S. Jorsater, P. O. Lindblad, and A. Sandqvist. The central region of NGC 613. evidence for an accelerated collimated outflow . A&A , 172 pp. 51–54, January 1987.
- [hummel_central_1992] E. Hummel and S. Jorsater. The central region of NGC 613 revisited . A&A , 261 pp. 85–93, July 1992.
- [kondratko_discovery_2006] P. T. Kondratko, L. J. Greenhill, J. M. Moran, J. E. J. Lovell, T. B. H. Kuiper, D. L. Jauncey, L. B. Cameron, J. F. Gómez, C. García-Miró, E. Moll, I. de Gregorio-Monsalvo, and E. Jiménez-Bailón. Discovery of water maser emission in eight AGNs with 70 m antennas of NASA's deep space network . ApJ , 638 pp. 100–105, February 2006.
- [roussel_atlas_2001] H. Roussel, L. Vigroux, A. Bosma, M. Sauvage, C. Bonoli, P. Gallais, T. Hawarden, J. Lequeux, S. Madden, and P. Mazzei. An atlas of mid-infrared dust emission in spiral galaxies . A&A , 369 pp. 473–509, April 2001.
- [veron_agns_1997] P. Veron, A. C. Goncalves, and M.-P. Veron-Cetty. AGNs with composite spectra. . A&A , 319 pp. 52–66, March 1997.
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.
Spitzer MIR images. Displayed are the inner 40 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 0.1% pixels with the highest intensity. The label in the bottom left states instrument and central wavelength of the filter in micron (I: IRAC, M: MIPS).
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.