Sasmirala – Individual Information for Mrk 304

Description

Mrk 304 is an ultra-luminous infrared, extremely compact galaxy at a redshift of z = 0.066 (D ~ 301 Mpc), hosting a radio-quiet borderline quasar with Sy 1 classification [veron-cetty_catalogue_2010]. No subarcsecond-resolution radio observations are reported in the literature, only a low-resolution point source was detected [kellermann_radio_1994]. Pioneering MIR observations were performed by [rieke_infrared_1978], followed by Spitzer/IRS and MIPS and appears as a compact source in the corresponding MIPS 24 μm image. The IRS LR staring-mode spectrum exhibits prominent silicate 10 and 18 μm emission and a blue spectral slope in νFν-space but no PAH features (see also [schweitzer_spitzer_2006, schweitzer_extended_2008, shi_aromatic_2007]). Mrk 304 was imaged with COMICS in the N11.7 filter in 2006 [imanishi_subaru_2011], and a compact nucleus without further host emission was detected. The nucleus appears to be marginally resolved (FWHM~ 0.56arcsec ~ 0.7 kpc) but at least another epoch of subarcsecond MIR imaging is required to verify this extension. Our nuclear N11.7 photometry is ~ 25% higher than the value by [imanishi_subaru_2011] for unknown reasons, and also higher than but still consistent with the Spitzer spectrophotometry. Therefore, we use the latter to compute the nuclear 12 μm continuum emission estimate corrected for the silicate feature. Note however, that the nuclear flux would be significantly lower if the presence of subarcsecond-extended emission can be verified. For now, the resulting synthetic flux is scaled by half of the ratio between FνPSF and FνGau to account for the possibly nuclear extension.

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.

Photometry details and reduced FITS files

ObjectRA
[deg]
Dec
[deg]
FilterImageInfoλ_c
[um]
HWHM
[um]
InstrPix. size
[arcsec/pix]
T_exp
[s]
ModeChop Throw
[arcsec]
Chop Angle
[deg]
Rot
[deg]
Prog IdCal. StarCal. DateDate Obs.Factor
[mJy/ct]
Err. Factor
[mJy/ct]
Cal. Flux
[mJy]
Upper Lim. Gauss?F_Gauss
[mJy]
E(F_Gauss)
[mJy]
Upper Lim. PSF?F_PSF
[mJy]
E(F_PSF)
[mJy]
Cal. Maj.
[arcsec]
Cal. Min.
[arcsec]
Cal. PA.
[deg]
Maj. Ax
[arcsec]
Min. Ax
[arcsec]
Pos. Ang.
[deg]
Mrk 304334.30125014.239167N11.7Mrk0304_N11.7_2006-10-04T06-09.fits[Details]11.740.53COMICS0.1332006.0PERP10.00.090.0o06139HD2064452006-10-04T04:48:00Z2006-10-04T06:08:38Z0.158020.007543869.3False98.07.2False47.53.30.40.37169.00.580.543.0