Sasmirala Individual Information for NGC 4278
Description
NGC 4278 is a radio-loud dusty elliptical galaxy at a distance of D = 16.1 ± 3.3 Mpc (NED redshift-independent median) with a broad-line LINER nucleus (see [pellegrini_agn_2012] for a recent detailed study). It features a compact flat-spectrum radio core with a parsec-scale two-sided jet (PA~-40∘; [giroletti_two-sided_2005, nagar_radio_2005]). The [O III] emission extends to kiloparsec-scales (PA~ 70∘; [sarzi_sauron_2006]). The first unsuccessful attempt to detect the nucleus of NGC 4278 in the MIR was made by [puschell_nonstellar_1981], while marginal detections are reported by [heckman_infrared_1983] and [impey_infrared_1986]. NGC 4278 was observed and detected by IRAS, ISO [xilouris_dust_2004, temi_cold_2004], and Spitzer/IRAC, IRS and MIPS [tang_infrared-red_2009, tang_multiphase_2011, dudik_spitzer_2009, pereira-santaella_mid-infrared_2010]. The corresponding IRAC and MIPS images are dominated by extended host emission without a clearly separable unresolved nuclear component. Our nuclear IRAC 5.8 and 8.0 μm and MIPS 24 μm photometry provides values in between the total and nuclear excess fluxes reported in [tang_infrared-red_2009]. The nuclear-extracted IRS spectrum exhibits possible weak silicate 10 and 18 μm emission, a PAH 11.3 μm feature and a blue curved spectral slope in νFν-space (see also [tang_multiphase_2011, mason_nuclear_2012]). Thus, the arcsecond-scale MIR SED is dominated by old-stellar host emission without significant star formation. The nuclear region of NGC 4278 was observed with Michelle in the N’ filter in 2008 [mason_nuclear_2012], and a compact nucleus is weakly detected. The low S/N of the detection prohibits any quantitative extension analysis. Our reanalysis of the image provides a nuclear flux value consistent with [mason_nuclear_2012] and ~ 80% lower than the Spitzer spectrophotometry.
- [dudik_spitzer_2009] R. P. Dudik, S. Satyapal, and D. Marcu. A spitzer spectroscopic survey of low-ionization nuclear emission-line regions: Characterization of the central source . ApJ , 691 pp. 1501–1524, February 2009.
- [giroletti_two-sided_2005] M. Giroletti, G. B. Taylor, and G. Giovannini. The two-sided parsec-scale structure of the low-luminosity active galactic nucleus in NGC 4278 . ApJ , 622 pp. 178–186, March 2005.
- [heckman_infrared_1983] T. M. Heckman, M. J. Lebofsky, G. H. Rieke, and W. van Breugel. An infrared and optical investigation of galactic nuclei with compact radio sources . ApJ , 272 pp. 400–410, September 1983.
- [impey_infrared_1986] C. D. Impey, C. G. Wynn-Williams, and E. E. Becklin. Infrared studies of elliptical galaxies. i - an optically selected sample . ApJ , 309 pp. 572–592, October 1986.
- [mason_nuclear_2012] R. E. Mason, E. Lopez-Rodriguez, C. Packham, A. Alonso-Herrero, N. A. Levenson, J. Radomski, C. Ramos Almeida, L. Colina, M. Elitzur, I. Aretxaga, P. F. Roche, and N. Oi. The nuclear infrared emission of low-luminosity active galactic nuclei. AJ , 144 pp. 11, July 2012.
- [nagar_radio_2005] N. M. Nagar, H. Falcke, and A. S. Wilson. Radio sources in low-luminosity active galactic nuclei. IV. radio luminosity function, importance of jet power, and radio properties of the complete palomar sample . A&A , 435 pp. 521–543, May 2005.
- [pellegrini_agn_2012] Silvia Pellegrini, Junfeng Wang, Giuseppina Fabbiano, Dong-Woo Kim, Nicola J. Brassington, John S. Gallagher, Ginevra Trinchieri, and Andreas Zezas. AGN activity and the misaligned hot ISM in the compact radio elliptical NGC 4278 . ApJ , 758 pp. 94, October 2012.
- [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.
- [puschell_nonstellar_1981] J. J. Puschell. Nonstellar 10 micron emission from E/S0 galaxies with compact radio sources . ApJ , 247 pp. 48–51, July 1981.
- [sarzi_sauron_2006] Marc Sarzi, Jesús Falcón-Barroso, Roger L. Davies, Roland Bacon, Martin Bureau, Michele Cappellari, P. Tim de Zeeuw, Eric Emsellem, Kambiz Fathi, Davor Krajnović, Harald Kuntschner, Richard M. McDermid, and Reynier F. Peletier. The SAURON project - v. integral-field emission-line kinematics of 48 elliptical and lenticular galaxies . MNRAS , 366 pp. 1151–1200, March 2006.
- [tang_infrared-red_2009] Yuping Tang, Q.-S. Gu, J.-S. Huang, and Y.-P. Wang. Infrared-red cores in nearby elliptical galaxies . MNRAS , 397 pp. 1966–1975, August 2009.
- [tang_multiphase_2011] Yuping Tang, Qiusheng Gu, Shuinai Zhang, and Baitian Tang. Multiphase dusty gas in the centre of NGC 4278 . MNRAS , 414 pp. 1827–1839, July 2011.
- [temi_cold_2004] Pasquale Temi, Fabrizio Brighenti, William G. Mathews, and Jesse D. Bregman. Cold dust in early-type galaxies. i. observations . ApJS , 151 pp. 237–269, April 2004.
- [xilouris_dust_2004] E. M. Xilouris, S. C. Madden, F. Galliano, L. Vigroux, and M. Sauvage. Dust emission in early-type galaxies: The mid-infrared view . A&A , 416 pp. 41–55, March 2004.
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.