Monitoring of the optical and 2.5-11.7 mu m spectrum and mid-IR imaging of the Seyfert 1 galaxy Mrk 279 with ISO
Altieri, B.;
Malkan, M. A.;
Clavel, J.;
Kriss, G. A.;
Crenshaw, D. M.;
Rodríguez-Pascual, P. M.;
Santos-Lleó, M.;
Netzer, H.;
Schulz, B.;
Reichert, G. A.;
Alloin, D.;
Krolik, J. H.;
Peterson, B. M.;
Wamsteker, W.;
Horne, K.;
O'Brien, P. T.;
Pogge, R. W.;
Wilkes, B. J.;
Huchra, J. P.;
Barr, P.;
Berlind, P.;
Bertram, R.;
Edelson, R. A.;
Giveon, U.;
Kaspi, S.;
Malkov, Yu. F.;
Pronik, V. I.;
Qian, B. -C.;
Sergeev, S. G.;
Tao, J.;
Tokarz, S.;
Wagner, R. M.
Spain, Netherlands, Chile, United States, United Kingdom, Israel, Ukraine, China
Abstract
Mid-infrared images of the Seyfert 1 galaxy Mrk 279 obtained with the ISO satellite are presented together with the results of a one-year monitoring campaign of the 2.5-11.7 mu m spectrum. Contemporaneous optical photometric and spectrophotometric observations are also presented. The galaxy appears as a point-like source at the resolution of the ISOCAM instrument (4-5arcsec ). The 2.5-11.7 mu m average spectrum of the nucleus in Mrk 279 shows a strong power law continuum with alpha = -0.80+/-0.05 ({ Fnu ~ nu alpha }) and weak PAH emission features. The Mrk 279 spectral energy distribution shows a mid-IR bump, which extends from 2 to 15-20 mu m . The mid-IR bump is consistent with thermal emission from dust grains at a distance of >~ 100 lt-d. No significant variations of the mid-IR flux have been detected during our observing campaign, consistent with the relatively low amplitude ( ~ 10% rms) of the optical variability during the campaign. The time delay for Hβ line emission in response to the optical continuum variations is tau = 16.7+5.3-5.6 days, consistent with previous measurements. Based on observations collected with the Infrared Space Observatory, ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands, and the UK) with the participation of ISAS and NASA. Tables 4 and 5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr 130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/369/57
2001
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Astronomy and Astrophysics
ISO
42
