Sasmirala Individual Information for NGC 7213

Description

NGC 7213 is a face-on lenticular galaxy at a redshift of z = 0.0058 (D ~ 23 Mpc) with a borderline Sy 1.5/LINER nucleus [phillips_optical_1979, filippenko_ngc_1984]. It has been studied well in X-rays and also belongs to the nine-month BAT AGN sample (see [bell_x-ray_2011] and [emmanoulopoulos_harder_2012] for a recent detailed study). The nucleus is unresolved at radio wavelengths down to milliarcsecond scales, has a flat radio spectrum, and has an intermediate radio-loudness [bransford_radio-luminous_1998, schmitt_jet_2001, thean_high-resolution_2000, blank_8.4-ghz_2005]. The [O III] morphology is halo-like with a diameter of ~ 1arcsec ~ 110 pc, slightly elongated into the east-west direction [schmitt_hubble_2003]. After first being detected in the MIR with IRAS, NGC 7213 was followed up from the ground [glass_mid-infrared_1982] and from space with Spitzer/IRAC, IRS and MIPS. The corresponding IRAC and MIPS images show a dominating compact nucleus embedded within weak spiral-like host emission. Our nuclear IRAC 5.8 and 8.0 μm photometry is significantly lower than the values published by [gallimore_infrared_2010] but in better agreement with the IRS LR staring-mode post-BCD spectrum. The latter is dominated by strong silicate 10 and 18 μm emission, a weak PAH 11.3 μm feature, and a flat spectral continuum slope in νF_ν-space (see also [shi_9.7_2006, wu_spitzer/irs_2009, deo_mid-infrared_2009, tommasin_spitzer-irs_2010, gallimore_infrared_2010]). Thus, the arcsecond-scale MIR SED indicates large amounts of AGN-heated dust and no significant star formation. We imaged the nuclear region of NGC 7213 with VISIR in total in four narrow N-band and one Q-band filters in 2006 [horst_mid_2008, horst_mid-infrared_2009] and 2009 (partly published in [asmus_mid-infrared_2011]), and obtained a VISIR LR N-band spectrum in 2008 [honig_dusty_2010-1]. In addition, it was imaged in the Si2 and Qa filters with T-ReCS in 2007, 2008 and 2010 (unpublished, to our knowledge). In all images, a compact nucleus without further host emission was detected. The nucleus appears essentially unresolved in the sharpest images (PAH2 from 2009, SIV from 2006 and NEII_1 from May 2009). Therefore we classify is as generally unresolved at subarcsecond resolution in the MIR. Note that the nucleus appears elongated in other PAH2 and NEII_1 images, which conclusively is not object intrinsic. The nuclear photometry indicates scatter of up to ~ 20% between lowest and highest fluxes (PAH2 2006 versus 2009), while being in general consistent with the VISIR N-band spectrum. The latter exhibits a ~ 20% lower continuum flux level than the Spitzer spectrophotometry with a similar silicate 10 μm emission strength and without and PAH emission. We use the VISIR spectrum to compute the 12 μm continuum emission estimate corrected for the silicate feature, which conclusively originates in the projected central ~ 40 pc of NGC 7213.

• [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.
• [bell_x-ray_2011] M. E. Bell, T. Tzioumis, P. Uttley, R. P. Fender, P. Arévalo, E. Breedt, I. McHardy, D. E. Calvelo, O. Jamil, and E. Körding. X-ray and radio variability in the low-luminosity active galactic nucleus NGC 7213 . MNRAS , 411 pp. 402–410, February 2011.
• [blank_8.4-ghz_2005] D. L. Blank, J. I. Harnett, and P. A. Jones. An 8.4-GHz long baseline array observation of the unusual seyfert galaxy NGC 7213 . MNRAS , 356 pp. 734–736, January 2005.
• [bransford_radio-luminous_1998] M. A. Bransford, P. N. Appleton, C. A. Heisler, R. P. Norris, and A. P. Marston. Radio-luminous southern seyfert galaxies. i. radio images and selected Optical/Near-Infrared spectroscopy . ApJ , 497 pp. 133, April 1998.
• [deo_mid-infrared_2009] Rajesh P. Deo, Gordon T. Richards, D. M. Crenshaw, and S. B. Kraemer. The mid-infrared continua of seyfert galaxies . ApJ , 705 pp. 14–31, November 2009.
• [emmanoulopoulos_harder_2012] D. Emmanoulopoulos, I. E. Papadakis, I. M. McHardy, P. Arévalo, D. E. Calvelo, and P. Uttley. The 'harder when brighter' x-ray behaviour of the low-luminosity active galactic nucleus NGC 7213 . MNRAS , 424 pp. 1327–1334, August 2012.
• [filippenko_ngc_1984] A. V. Filippenko and J. P. Halpern. NGC 7213 - a key to the nature of liners? . ApJ , 285 pp. 458–474, October 1984.
• [gallimore_infrared_2010] J. F. Gallimore, A. Yzaguirre, J. Jakoboski, M. J. Stevenosky, D. J. Axon, S. A. Baum, C. L. Buchanan, M. Elitzur, M. Elvis, C. P. O'Dea, and A. Robinson. Infrared spectral energy distributions of seyfert galaxies: Spitzer space telescope observations of the 12 μm sample of active galaxies . ApJS , 187 pp. 172–211, March 2010.
• [glass_mid-infrared_1982] I. S. Glass, A. F. M. Moorwood, and W. Eichendorf. Mid-infrared observations of seyfert 1 and narrow-line x-ray galaxies . A&A , 107 pp. 276–282, March 1982.
• [honig_dusty_2010-1] S. F. Hönig, M. Kishimoto, P. Gandhi, A. Smette, D. Asmus, W. Duschl, M. Polletta, and G. Weigelt. The dusty heart of nearby active galaxies. i. high-spatial resolution mid-IR spectro-photometry of seyfert galaxies . A&A , 515 pp. 23, June 2010.
• [horst_mid-infrared_2009] H. Horst, W. J. Duschl, P. Gandhi, and A. Smette. Mid-infrared imaging of 25 local AGN with VLT-VISIR . A&A , 495 pp. 137–146, February 2009.
• [horst_mid_2008] H. Horst, P. Gandhi, A. Smette, and W. J. Duschl. The mid IR - hard x-ray correlation in AGN and its implications for dusty torus models . A&A , 479 pp. 389–396, February 2008.
• [phillips_optical_1979] M. M. Phillips. Optical spectrophotometry of the suspected x-ray galaxies NGC 6221 and NGC 7213 . ApJL , 227 pp. L121, February 1979.
• [schmitt_hubble_2003] H. R. Schmitt, J. L. Donley, R. R. J. Antonucci, J. B. Hutchings, and A. L. Kinney. A hubble space telescope survey of extended [o III] λ5007 emission in a far-infrared selected sample of seyfert galaxies: Observations . ApJS , 148 pp. 327–352, October 2003.
• [schmitt_jet_2001] H. R. Schmitt, J. S. Ulvestad, R. R. J. Antonucci, and A. L. Kinney. Jet directions in seyfert galaxies: Radio continuum imaging data . ApJS , 132 pp. 199–209, February 2001.
• [shi_9.7_2006] Y. Shi, G. H. Rieke, D. C. Hines, V. Gorjian, M. W. Werner, K. Cleary, F. J. Low, P. S. Smith, and J. Bouwman. 9.7 μm silicate features in active galactic nuclei: New insights into unification models . ApJ , 653 pp. 127–136, December 2006.
• [thean_high-resolution_2000] Andy Thean, Alan Pedlar, Marek J. Kukula, Stefi A. Baum, and Christopher P. O'Dea. High-resolution radio observations of seyfert galaxies in the extended 12-μm sample - i. the observations . MNRAS , 314 pp. 573–588, May 2000.
• [tommasin_spitzer-irs_2010] Silvia Tommasin, Luigi Spinoglio, Matthew A. Malkan, and Giovanni Fazio. Spitzer-IRS high-resolution spectroscopy of the 12 μm seyfert galaxies. II. results for the complete data set . ApJ , 709 pp. 1257–1283, February 2010.
• [wu_spitzer/irs_2009] Yanling Wu, Vassilis Charmandaris, Jiasheng Huang, Luigi Spinoglio, and Silvia Tommasin. Spitzer/IRS 5-35 μm low-resolution spectroscopy of the 12 μm seyfert sample . ApJ , 701 pp. 658–676, August 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.