ﻻ يوجد ملخص باللغة العربية
Data from the Spitzer Space Telescope (the First Look Survey - FLS) have recently been made public. We have compared the 24 micron images with very deep WSRT 1.4 GHz observations (Morganti et al. 2004), centred on the FLS verification strip (FLSv). Approximately 75% of the radio sources have corresponding 24 micron identifications. Such a close correspondence is expected, especially at the fainter radio flux density levels, where star forming galaxies are thought to dominate both the radio and mid-IR source counts. Spitzer detects many sources that have no counter-part in the radio. However, a significant fraction of radio sources detected by the WSRT (about 25%) have no mid-IR identification in the FLSv (implying a 24 micron flux density less than 100 microJy). The fraction of radio sources without a counterpart in the mid-IR appears to increase with increasing radio flux density, perhaps indicating that some fraction of the AGN population may be detected more readily at radio than Mid-IR wavelenghts. We present initial results on the nature of the radio sources without Spitzer identification, using data from various multi-waveband instruments, including the publicly available R-band data from the Kitt Peak 4-m telescope.
We present MAMBO 1.2mm observations of 40 extragalactic sources from the Spitzer First Look Survey that are bright in the mid-infrared (S_24um>1mJy) but optically obscured (log_10 (nu F_nu (24um))/(nu F_nu (0.7um))>1). We use these observations to se
Data from the Spitzer Space Telescope (the First Look Survey - FLS) have recently been made public. We have compared the 24 micron images with very deep WSRT 1.4 GHz observations, centred on the FLS verification strip (FLSv). Approximately 75% of the
The Spitzer Space Telescope has undertaken the deepest ever observations of the 24 micron sky in the ELAIS-N1 field as part of GOODS Science Verification observations. We present the shape of the 24 micron source counts in the flux range 20-1000 micr
We present high spatial resolution MIR observations for several nearby radio loud active galactic nuclei (RLAGN), which were obtained using the Gemini North and South telescopes. Of the six observed objects, we detected five in the Si-2 (8.7 microns)
Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4GHz, but that are invisible at 3.6um when using sensitive Spitzer observations with uJy sensitivities. Their nature is unclear and difficult to investigate