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-Cygni – before GLAST

-Cygni – before GLAST. Alberto Carramiñana Instituto Nacional de Astrof ísica, Óptica y Electrónica Tonantzintla, México The Multimessenger approach to HE -ray sources Barcelona, 4- 7 july 2006. The -source 2CG 078+2. One of 25 Cos-B sources Located in the Cygnus region

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-Cygni – before GLAST

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  1. -Cygni – before GLAST Alberto Carramiñana Instituto Nacional de Astrofísica, Óptica y Electrónica Tonantzintla, México The Multimessenger approach to HE -ray sources Barcelona, 4- 7 july 2006

  2. The -source 2CG 078+2 • One of 25 Cos-B sources • Located in the Cygnus region • Also 2EG J2020+4026, GeV J2020+4023, 3EG J2020+4017: • F(>100 MeV)= 1.2310-6 cm-2s-1 → EF~210-10erg cm-2s-1 the brightest unidentified EGRET source • steady source, hard spectrum =–2.08 • break at 4 GeV (photons up to 16 and 18 GeV)

  3. Identifiyng 2EG J2020+4026 • Located at • 20:20:34 +40:26:24 -- 8’ radius (95% CL) • GeV photons 20:20:15 +40:21:00 -- 2014’ box (95% CL) • Inside SNR -Cygni (G78.2+2.1 @ 1.5 kpc) • No pulsations detectable in EGRET data • Unresolved with R<0.5 • Multiwavelength ID approach, “Geminga-like” Brazier et al. MNRAS 281, 1033 (1996)

  4. Identifying 2EG J2020+4026 • ROSAT PSPC data on -Cygni SNR • One X-ray point source: RX J2020.2+4026 • Fx ~ 410-14 erg cm-2s-1→ F/Fx  5000 • no radio F400<600 mJy • A 15-mag star in 5” error box (type K0V) - ruled out as RX J2020.2+4026 and 2EG J2020+4026 Brazier et al. (1996)

  5. Becker et al. ApJ 615, 897 (2004) A deeper look • Now to 3EG J2020+4017 • at 20:21:01 +40:17:48 (displaced +.10,-.14º) • RX J2020.2+4026 outside 95% (in 99%) • Chandra observations of RX 2020.2+4026 • coincident with K star • Fit to ROSAT-HRI points to d<356 pc distance • Partial coverage of 3EG error box • 38 cxo sources! RX J2020.2+4026 • GBT on entire 99% 3EG box • S820<40Jy, S1400<20Jy • radio quiet box

  6. Weisskopf et al. astro-ph/0606596 3EG J2020+4017 (II) • Chandra observation of 3EG box • 30 point sources • Sx~ 10-13 to 10-14 erg cm-2 s-1

  7. S(0.5-8 keV) 10-15 erg cm-2s-1 1-30 → S/Sx > 2000 - 20000

  8. ← ← ← ← ← ← ← ← ← ← ← ← Too many candidates left!!

  9. The -source 2CG 078+2 • Uncertainty in error box location • 2EG = (305.14, 40.44) ± 0.15º • GeV = (305.07, 40.35) ± (0.30,0.25) º • 3EG = (305.25, 40.29) ± 0.15º • Coincidence with SNR call for PSR-ID • S/Sx > 2000 - 20000 • Optical? • Radio below 40 Jy – definitively radio quiet! It will get it!

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