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J/ApJ/705/14       Seyfert galaxies in the mid-IR          (Deo+, 2009)

The mid-infrared continua of Seyfert galaxies. Deo R.P., Richards G.T., Crenshaw D.M., Kraemer S.B. <Astrophys. J., 705, 14-31 (2009)> =2009ApJ...705...14D
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; Spectra, infrared Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert - infrared: galaxies Abstract: An analysis of archival mid-infrared (mid-IR) spectra of Seyfert galaxies from the Spitzer Space Telescope observations is presented. We characterize the nature of the mid-IR active nuclear continuum by subtracting a template starburst spectrum from the Seyfert spectra. The long wavelength part of the spectrum contains a strong contribution from the starburst-heated cool dust; this is used to effectively separate starburst-dominated Seyferts from those dominated by the active nuclear continuum. Within the latter category, the strength of the active nuclear continuum drops rapidly beyond ∼20um. On average, type 2 Seyferts have weaker short-wavelength active nuclear continua as compared to type 1 Seyferts. Type 2 Seyferts can be divided into two types, those with strong polycyclic aromatic hydrocarbon (PAH) bands and those without. Description: We primarily use archival Spitzer InfraRed Spectrograph spectra extracted from programs 3069 (PI: J. Gallimore, mapping-mode spectra), 3374 (PI: S. Kraemer, staring mode spectra) and Weedman et al. (2005ApJ...633..706W; Mrk 3, low-resolution staring mode spectrum). Deo et al. (2007ApJ...671..124D) presented single slit extractions of spectra from above-mentioned programs for about half of the current sample. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 94 109 Observation summary, redshifts, optical Seyfert types, and extraction apertures table2.dat 117 108 Continuum flux densities and apparent optical depth at 9.7um table3.dat 61 93 Starburst-to-AGN flux density ratios
See also: VII/248 : Quasars and Active Galactic Nuclei (12th Ed.) (Veron+ 2006) VII/173 : Catalogue of Seyfert Galaxies (Lipovetsky+, 1988) J/A+A/473/369 : VISIR/VLT mid-infrared imaging of Seyfert nuclei (Haas+, 2007) J/A+A/418/465 : Mid-infrared and hard X-ray emission in AGN (Lutz+, 2004) J/ApJS/125/349 : Morphology of 12micron Seyfert Galaxies (Hunt+, 1999) J/other/PBeiO/18.7 : Far infrared Seyfert galaxies (Liu 1991) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Galaxy name 21- 28 F8.6 --- z NED redshift 30- 33 A4 --- SyT Seyfert type (1) 35- 38 F4.2 --- b/a Axial ratio (2) 40- 47 I8 --- AOR Spitzer archive AOR number 49 A1 --- Obs [SM] Observing mode for Spitzer/IRS spectrum: (S=staring or M=mapping) 51- 60 F10.6 deg RAdeg ? Extraction rectangle for mapping mode: right ascension in decimal degrees (J2000) (3) 62- 71 F10.6 deg DEdeg ? Extraction rectangle for mapping mode: declination in decimal degrees (J2000) (3) 73- 78 F6.3 arcsec Ap1 ? First extraction aperture 79 A1 --- --- [x] 80- 85 F6.3 arcsec Ap2 ? Second extraction aperture 87- 94 F8.2 pc/arcsec scale Radial extent of the extraction aperture for the galaxy
Note (1): Seyfert type from Veron-Cetty & Veron (2006, Cat. VII/248; superseded by Cat. VII/258) as follows: S1 = Seyfert 1 optical spectrum; S1h = broad polarized Balmer lines detected; S1i = broad Paschen lines observed in the infrared; S1n = narrow-line Seyfert 1; S1.0, S1.2, S1.5, S1.8, and S1.9 = intermediate Seyfert galaxies (Note: In this paper, we consider S1.0-1.5 to be broadly Seyfert 1s in all analysis.); S2 = Seyfert 2 spectrum; S3 = LINER; S3b = LINER with broad Balmer lines; S3h = LINER with broad polarized Balmer lines detected; H2 = nuclear HII region Note (2): Axial ratio, minor-to-major axis ratio of host galaxy obtained from NED, for host galaxies where b/a was not available we assumed it to be 1. Note (3): Extraction rectangle for mapping-mode spectra: R.A. and Decl. of center-point.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Galaxy name 21- 28 E8.3 Jy 5.5um ? Spitzer/IRS 5.5um continuum flux density 30- 37 E8.3 Jy 10um ? Spitzer/IRS 10um continuum flux density 39- 46 E8.3 Jy 14.7um ? Spitzer/IRS 14.7um continuum flux density 48- 55 E8.3 Jy 20um ? Spitzer/IRS 20um continuum flux density 57- 64 E8.3 Jy 30um ? Spitzer/IRS 30um continuum flux density 66- 72 F7.4 --- tau ? Observed optical depth (apparent) at 9.7um 74- 81 E8.3 Jy e_5.5um ? 1σ error in 5.5um 83- 90 E8.3 Jy e_10um ? 1σ error in 10um 92- 99 E8.3 Jy e_14.7um ? 1σ error in 14.7um 101-108 E8.3 Jy e_20um ? 1σ error in 20um 110-117 E8.3 Jy e_30um ? 1σ error in 30um
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 19 A19 --- Name Galaxy name 21- 26 F6.4 --- R5.5 ? Starbust-to-AGN flux density ratio at 5.5um (1) 28- 34 F7.4 --- R10 ? Starbust-to-AGN flux density ratio at 10um (1) 36- 44 F9.4 --- R14.7 ? Starbust-to-AGN flux density ratio at 14.7um (1) 46- 53 F8.4 --- R20 ? Starbust-to-AGN flux density ratio at 20um (1) 55- 61 F7.4 --- R30 ? Starbust-to-AGN flux density ratio at 30um (1)
Note (1): A missing ratio implies either the spectrum was incomplete at that wavelength or the AGN contribution was negative after starburst subtraction. A very large ratio indicates very weak AGN contribution, these typically occur at or beyond 14.7um in a few galaxies. See Figure 10 for a visual representation of these ratios, and Table 1 for aperture size in parsecs. Even in nearby AGN, Spitzer spectra sample regions of size ∼1kpc. See Section 5 for discussion of the starburst subtraction process and results.
History: From electronic version of the journal
(End) Emmanuelle Perret [CDS] 28-Nov-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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