Sasmirala Individual Information for NGC 3185

Description

NGC 3185 is an inclined spiral galaxy at a distance of D = 20.3 ± 6.1 Mpc [springob_erratum:_2009] with a possible AGN, optically classified as a borderline Sy 2/H II nucleus [ho_search_1997-1, goncalves_agns_1999]. The nucleus is only marginally detected at radio wavelengths (e.g., [ho_radio_2001]). The nucleus of NGC 3185 was first observed with IRTF [devereux_infrared_1987] and MMT [maiolino_new_1995], in which it was weakly detected at ~ 20 mJy. In the Spitzer/IRAC and MIPS images, a compact nucleus embedded within the spiral-like host emission was detected. The nucleus is extended in the IRAC images. The Spitzer/IRS LR staring-mode spectrum is dominated by PAH emission linked to star formation, a possible weak silicate 10 μm absorption feature and a red spectral slope in νF_ν-space. At subarcsecond-resolution, the nuclear region of NGC 3185 was observed with VISIR in the PAH1 filter in 2010 (unpublished, to our knowledge), but the nucleus remained undetected. Our derived flux upper limit is ~ 62% lower than the Spitzer spectrophotometry, which is consistent with the historical measurements. This result demonstrates that star formation is dominating the MIR emission of the central ~ 0.4 kpc in NGC 3185. Note however that [pereira-santaella_mid-infrared_2010] claims the detection of [Ne V], which supports the presence of an AGN in this object.

• [devereux_infrared_1987] Nicholas A. Devereux, E. E. Becklin, and Nick Scoville. Infrared characteristics of the nuclei of normal galaxies . ApJ , 312 pp. 529–541, January 1987.
• [goncalves_agns_1999] A. C. Gonçalves, M.-P. Véron-Cetty, and P. Véron. AGNs with composite spectra. II. additional data . A&AS , 135 pp. 437–466, March 1999.
• [ho_radio_2001] Luis C. Ho and James S. Ulvestad. Radio continuum survey of an optically selected sample of nearby seyfert galaxies . ApJS , 133 pp. 77–118, March 2001.
• [ho_search_1997-1] Luis C. Ho, Alexei V. Filippenko, and Wallace L. W. Sargent. A search for ``Dwarf'' seyfert nuclei. III. spectroscopic parameters and properties of the host galaxies . ApJS , 112 pp. 315, October 1997.
• [maiolino_new_1995] R. Maiolino, M. Ruiz, G. H. Rieke, and L. D. Keller. New constraints on the unified model of seyfert galaxies . ApJ , 446 pp. 561, June 1995.
• [pereira-santaella_mid-infrared_2010] Miguel Pereira-Santaella, Aleksandar M. Diamond-Stanic, Almudena Alonso-Herrero, and George H. Rieke. The mid-infrared high-ionization lines from active galactic nuclei and star-forming galaxies . ApJ , 725 pp. 2270–2280, December 2010.
• [springob_erratum:_2009] Christopher M. Springob, Karen L. Masters, Martha P. Haynes, Riccardo Giovanelli, and Christian Marinoni. Erratum: "SFI++ II: a new i-band tully-fisher catalog, derivation of peculiar velocities and data set properties" (2007, ApJS, 172, 599) . ApJS , 182 pp. 474–475, May 2009.

Images

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.