1 2009 Fermi Symposium, Washington, D.C., Nov. 2-5 Extensive near infrared monitoring of millimeter-wave / gamma-ray bright blazars We established a sample of millimeter-wave and γ -ray bright active galactic nuclei matching the WMAP catalog with the EGRET catalog, highest energy photons and the Fermi bright source list. We have monitored over 80 of these objects in the near infrared, obtaining over 2000 JHKs data points directly comparable with Fermi data. We present examples of correlated near infrared and γ -ray activity of known blazars and recently identified sources. Alberto Carrami˜ nana, Luis Carrasco, Alicia Porras, Elsa Recillas INAOE, Luis Enrique Erro 1, Tonantzintla, Puebla 72840, M´exico CGRO -EGRET established the predominance of flat spectrum radio quasars (FSRQ) as extragalactic sources of high-energy γ -rays [1]. These are believed to be powered by supermassive black holes ejecting large amounts of material along relativistic jets per- pendicular to accretion disks and producing high en- ergy particles in these jets. Observations at the high- est photon energies shown a predominance of Bl Lac objects over FSRQ at E ∼ 1 TeV. Although these observations may be biased by the horizon limita- tion due to pair absorption with extragalactic back- ground light (EBL), the Fermi γ -ray Space Telescope, more sensitive and more responsive to GeV photons than EGRET, reported a larger fraction of Bl Lac objects among blazars in its bright source list release (0FGL) [2, 3]. The wider spectral coverage of Fermi is allowing detailed studies of the intrinsic properties of various types of active galactic nuclei (AGN), cosmic evolution and their use as EBL tracers [4]. As a by product of the study of the cosmic microwave background, the Wilkinson Microwave Anisotropy Probe (WMAP) produced a catalog of 390 bright sources detected at frequencies between 23 and 94 GHz, outside a mask defined by the mm-wave emis- sion from the Galactic plane [5]. These objects con- stitute a fairly homogeneous sample suitable for com- parison with all-sky γ -ray catalogs. We compared the WMAP foreground source cat- alog [5] with: (1) the Third EGRET (3EG) catalog of high-energy γ -ray sources [1]; (2) the E > 10 GeV EGRET photons compiled by [7]; (3) the list of bright $_{sources detected with signal-to-noise (}$√$_{T S}$$_{) larger}$ than 10 by the Fermi γ -ray Space Telescope in its first three months of operations [2]. The positional uncer- tainty of WMAP equals 4 $^{′}$, similar to that of Fermi , but much better than that of EGRET. Preferring to accept false positives than to reject real coincidences, we used a relaxed matching criterion of 2.5 times the combined positional accuracy, ( σ 2 wmap + σ 2 $_{γ}$) 1 / $^{2}$, where σ$_{γ}$ $^{refers to 3EG (}$∼ 1 $^{◦}$), EGRET-VHE (0 . 5 $^{◦}$) $^{or 0FGL (2}$− 10 $^{′}$). For each comparison we estimated the expected number of random coincidences quanti- fying the solid angle covered by the γ -ray sources (or events) outside the WMAP Galactic mask. For each WMAP / γ pair we blindly listed potential radio, op- tical and X-ray counterparts from SIMBAD / Vizier. The results are listed in tables II and III. The extrapolation of FSRQ to high radio frequen- cies makes the coincidence of foreground WMAP sources with γ -ray blazars expectable. Furthermore, it is clear than most of the 390 WMAP sources are AGNs [5]. These emitters are dominated in the mm-wave band by the same synchrotron com- ponent observed at lower frequencies and can be expected to emit photons of very high energy, re- lated to the hardest part of the synchrotron emission. WMAP sources have fluxes above 0.1 Jy at frequen- cies > ∼ 40 GHz, making them suitable positional refer- ences for large millimeter telescopes. Known common WMAP /EGRET sources, found up to z > ∼ 2 . 3, are relatively nearby analogs of more distant blazars de- tectable in principle by Fermi up to z > ∼ 7 and by the Large Millimeter Telescope (LMT [6]) at z > ∼ 30, if such an object could have existed at such an early phase of the Universe. The combination of Fermi and LMT data promises the availability of a sample of thousands of objects up to the highest redshifts ide- ally suited to study radio loud AGN evolution and the connection of the EBL with the star formation history of the Universe. eConf C091122 arXiv:1001.0204v1 [astro-ph.HE] 1 Jan 2010 II. MATCHING WMAP WITH γ -RAY SOURCES I. MM-WAVE γ -RAY BRIGHT BLAZARS TABLE I: WMAP and EGRET source matches by type. ( † = excludes P, G and S types [1]). Source 3EG WMAP Matches Type catalog mask Observed Expected A 67 54 40 6.6 a 28 23 17 3.3 U 170 61 11 10.0 Total 265 † 138 68 20