Sasmirala Individual Information for NGC 3627
Description
NGC 3627 is a grand-design spiral galaxy in the Leo Triplet at a distance of D = 10.1 ± 1.7 Mpc (NED redshift-independent median) with an active nucleus either classified as a transition/Sy 2 [ho_search_1997-1] or a LINER [veron-cetty_catalogue_2010]. It is in tidal interaction with NGC 3628 [zhang_high-resolution_1993]. The first N-band photometry was taken by [rieke_infrared_1972] and [rieke_10_1978]. Since IRAS, Spitzer/IRAC, IRS and MIPS observations followed. The IRAC and MIPS images show a compact nucleus with surrounding spiral-like host emission. Because we measure the photometry of the nuclear component only, our IRAC 5.8 and 8.0 μm and MIPS 24 μm fluxes are significantly lower than the values in the literature (e.g., [dale_infrared_2005, dale_spitzer_2009, munoz-mateos_radial_2009]). Owing to the complex emission morphology of NGC 3627 in the MIR, the IRS LR mapping-mode PBCD spectrum is not very reliable. However, it roughly matches the IRAC photometry and exhibits strong PAH emission with possibly weak silicate 10 μm absorption, i.e., star formation in the central 4arcsec~ 200 pc region (see e.g., [dale_spitzer_2009, goulding_towards_2009]). NGC 3627 was observed with VISIR in the PAH1 filter in 2010 (unpublished, to our knowledge). An north-south elongated structure (~ 2arcsec ~ 100 pc) matching the larger scale morphology seen in IRAC in orientation is weakly detected. We measure the nuclear unresolved component with a flux only 6% of that in Spitzer. However, the unresolved component is not clearly separable from the extended emission. Therefore, our nuclear 12 μm continuum emission estimate should be regarded as an upper limit for any AGN. The nucleus has not been detected in X-rays so far [ho_detection_2001, filho_further_2004] but is clearly present at radio wavelengths [filho_nature_2000]. If an AGN is present in this object it is most likely heavily obscured and embedded in nuclear star formation (see also [gonzalez-martin_fitting_2009, masegosa_nature_2011]).
- [dale_infrared_2005] D. A. Dale, G. J. Bendo, C. W. Engelbracht, K. D. Gordon, M. W. Regan, L. Armus, J. M. Cannon, D. Calzetti, B. T. Draine, G. Helou, R. D. Joseph, R. C. Kennicutt, A. Li, E. J. Murphy, H. Roussel, F. Walter, H. M. Hanson, D. J. Hollenbach, T. H. Jarrett, L. J. Kewley, C. A. Lamanna, C. Leitherer, M. J. Meyer, G. H. Rieke, M. J. Rieke, K. Sheth, J. D. T. Smith, and M. D. Thornley. Infrared spectral energy distributions of nearby galaxies . ApJ , 633 pp. 857–870, November 2005.
- [dale_spitzer_2009] D. A. Dale, J. D. T. Smith, E. A. Schlawin, L. Armus, B. A. Buckalew, S. A. Cohen, G. Helou, T. H. Jarrett, L. C. Johnson, J. Moustakas, E. J. Murphy, H. Roussel, K. Sheth, S. Staudaher, C. Bot, D. Calzetti, C. W. Engelbracht, K. D. Gordon, D. J. Hollenbach, R. C. Kennicutt, and S. Malhotra. The spitzer infrared nearby galaxies survey: A high-resolution spectroscopy anthology . ApJ , 693 pp. 1821–1834, March 2009.
- [filho_further_2004] M. E. Filho, F. Fraternali, S. Markoff, N. M. Nagar, P. D. Barthel, L. C. Ho, and F. Yuan. Further clues to the nature of composite LINER/H II galaxies . A&A , 418 pp. 429–443, May 2004.
- [filho_nature_2000] Mercedes E. Filho, Peter D. Barthel, and Luis C. Ho. The nature of composite LINER/H II galaxies as revealed from high-resolution VLA observations . ApJS , 129 pp. 93–110, July 2000.
- [gonzalez-martin_fitting_2009] O. González-Martín, J. Masegosa, I. Márquez, and M. Guainazzi. Fitting liner nuclei within the active galactic nucleus family: A matter of obscuration? . ApJ , 704 pp. 1570–1585, October 2009.
- [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.
- [ho_detection_2001] Luis C. Ho, Eric D. Feigelson, Leisa K. Townsley, Rita M. Sambruna, Gordon P. Garmire, W. N. Brandt, Alexei V. Filippenko, Richard E. Griffiths, Andrew F. Ptak, and Wallace L. W. Sargent. Detection of nuclear x-ray sources in nearby galaxies with chandra . ApJ , 549 pp. L51–L54, 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.
- [masegosa_nature_2011] J. Masegosa, I. Márquez, A. Ramirez, and O. González-Martín. The nature of nuclear hα emission in LINERs . A&A , 527 pp. 23, March 2011.
- [munoz-mateos_radial_2009] J. C. Muñoz-Mateos, A. Gil de Paz, J. Zamorano, S. Boissier, D. A. Dale, P. G. Pérez-González, J. Gallego, B. F. Madore, G. Bendo, A. Boselli, V. Buat, D. Calzetti, J. Moustakas, and R. C. Kennicutt. Radial distribution of stars, gas, and dust in SINGS galaxies. i. surface photometry and morphology . ApJ , 703 pp. 1569–1596, October 2009.
- [rieke_10_1978] G. H. Rieke and M. J. Lebofsky. 10 micron observations of bright galaxies . ApJL , 220 pp. L37–L41, March 1978.
- [rieke_infrared_1972] G. H. Rieke and F. J. Low. Infrared photometry of extragalactic sources . ApJL , 176 pp. L95, September 1972.
- [veron-cetty_catalogue_2010] M.-P. Véron-Cetty and P. Véron. A catalogue of quasars and active nuclei: 13th edition . A&A , 518 pp. 10, July 2010.
- [zhang_high-resolution_1993] Xiaolei Zhang, Melvyn Wright, and Paul Alexander. High-resolution CO and h i observations of the interacting galaxy NGC 3627 . ApJ , 418 pp. 100, November 1993.
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.