Sasmirala Individual Information for NGC 5728

Description

NGC 5728 is an inclined barred spiral galaxy at a redshift of z = 0.0094 (D ~ 45.4 Mpc) hosting a Sy 1.9 nucleus [pecontal_observation_1990], which is commonly referred to as a Sy 2 type in the literature (e.g. [tueller_swift_2008]). It belongs to the nine-month BAT AGN sample. The nucleus features a compact radio core with one-sided extension up to ~ 5arcsec ~ 1 kpc to the north-west (PA~-53^∘; [schommer_ionized_1988]) and a cospatial biconical kiloparsec-scale NLR (PA~ 130^∘; [pogge_circumnuclear_1989, wilson_ionization_1993]). In addition, disc-like water maser emission was detected [braatz_green_2004]. After being detected in the MIR with IRAS for the first time, NGC 5728 was followed up with ISO [clavel_2.5-11_2000, ramos_almeida_mid-infrared_2007] and Spitzer/IRAC, IRS and MIPS. The corresponding IRAC and MIPS images show a compact nucleus embedded within bright disc-like emission with ~ 13arcsec ~ 2.8 kpc diameter and fainter spiral-like host emission on larger scales. The IRS LR staring-mode spectrum exhibits deep silicate 10 μm absorption, prominent PAH emission, forbidden emission lines, and a red spectral slope in νF_ν-space (see also [weaver_mid-infrared_2010, pereira-santaella_mid-infrared_2010]). Thus, the arcsecond-scale MIR SED appears to be star-formation dominated. The nuclear region of NGC 5728 was observed with T-ReCS in the Si2 and Qa filters in 2005 [ramos_almeida_infrared_2009], and with VISIR in five narrow N-band filters in 2008 [gandhi_resolving_2009] and 2010 (this work). A compact nucleus without further host emission was detected in all images, except PAH1 and SIV. The nucleus appears marginally resolved and roundish in the images, but the nuclear FWHM of the individual images do not match. We measure only the unresolved nuclear fluxes, which are on average ~ 30% lower than the nuclear fluxes published in [ramos_almeida_infrared_2009] and [gandhi_resolving_2009] and also ~ 62% lower than the Spitzer spectrophotometry. The nuclear MIR SED indicates a silicate 10 μm absorption depth similar to the Spitzer data, but the PAH features are much. However, it might still be significantly affected by star-formation caused MIR emission. We conclude that the silicate absorption is produced in the projected central ~ 75 pc of NGC 5728.

• [braatz_green_2004] J. A. Braatz, C. Henkel, L. J. Greenhill, J. M. Moran, and A. S. Wilson. A green bank telescope search for water masers in nearby active galactic nuclei . ApJL , 617 pp. L29–L32, December 2004.
• [clavel_2.5-11_2000] J. Clavel, B. Schulz, B. Altieri, P. Barr, P. Claes, A. Heras, K. Leech, L. Metcalfe, and A. Salama. 2.5-11 micron spectroscopy and imaging of AGNs. implication for unification schemes . A&A , 357 pp. 839–849, May 2000.
• [gandhi_resolving_2009] P. Gandhi, H. Horst, A. Smette, S. Hönig, A. Comastri, R. Gilli, C. Vignali, and W. Duschl. Resolving the mid-infrared cores of local seyferts . A&A , 502 pp. 457–472, August 2009.
• [pecontal_observation_1990] E. Pecontal, G. Adam, R. Bacon, G. Courtes, Y. Georgelin, and G. Monnet. Observation of the central region of NGC 5728 with the integral field spectrograph TIGER . A&A , 232 pp. 331–336, June 1990.
• [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.
• [pogge_circumnuclear_1989] Richard W. Pogge. The circumnuclear environment of nearby, noninteracting seyfert galaxies . ApJ , 345 pp. 730–751, October 1989.
• [ramos_almeida_infrared_2009] C. Ramos Almeida, N. A. Levenson, J. M. Rodríguez Espinosa, A. Alonso-Herrero, A. Asensio Ramos, J. T. Radomski, C. Packham, R. S. Fisher, and C. M. Telesco. The infrared nuclear emission of seyfert galaxies on parsec scales: Testing the clumpy torus models . ApJ , 702 pp. 1127–1149, September 2009.
• [ramos_almeida_mid-infrared_2007] C. Ramos Almeida, A. M. Pérez García, J. A. Acosta-Pulido, and J. M. Rodríguez Espinosa. The mid-infrared emission of seyfert galaxies: A new analysis of ISOCAM data . AJ , 134 pp. 2006–2019, November 2007.
• [schommer_ionized_1988] Robert A. Schommer, Nelson Caldwell, A. S. Wilson, J. A. Baldwin, M. M. Phillips, T. B. Williams, and A. J. Turtle. Ionized gas and radio emission in the barred seyfert galaxy NGC 5728 . ApJ , 324 pp. 154–171, January 1988.
• [tueller_swift_2008] J. Tueller, R. F. Mushotzky, S. Barthelmy, J. K. Cannizzo, N. Gehrels, C. B. Markwardt, G. K. Skinner, and L. M. Winter. Swift BAT survey of AGNs . ApJ , 681 pp. 113–127, July 2008.
• [weaver_mid-infrared_2010] K. A. Weaver, M. Meléndez, R. F. Mushotzky, S. Kraemer, K. Engle, E. Malumuth, J. Tueller, C. Markwardt, C. T. Berghea, R. P. Dudik, L. M. Winter, and L. Armus. Mid-infrared properties of the swift burst alert telescope active galactic nuclei sample of the local universe. i. emission-line diagnostics . ApJ , 716 pp. 1151–1165, June 2010.
• [wilson_ionization_1993] A. S. Wilson, J. A. Braatz, T. M. Heckman, J. H. Krolik, and G. K. Miley. The ionization cones in the seyfert galaxy NGC 5728 . ApJL , 419 pp. L61, December 1993.

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.