1. Galactic Gamma-Ray Transients with AGILE
A. Chen
on behalf of the AGILE Team
7th AGILE Workshop
ESRIN, 30 September, 2009

2. Continuous monitoring of sources in the FOV
AGILE capabilities
Continuous monitoring of sources in the FOV
SAA and Earth occultation
Good sensitivity near 100 MeV
Simultaneous hard X-ray and gamma-ray monitoring
Ideal for Microquasar studies

3. The AGILE 1-day exposure (E > 100 MeV)
(30 Nov. 2008)

4. AGILE-GRID telemetry on Nov. 3, 2008

5. AGILE gamma-ray map, Nov. 3, 2008

6. a comparison: 1-day exposure
AGILE (GRID)
FERMI (LAT)
FOV (sr)
2.5
sky coverage
1/5
whole sky
Source livetime fraction
~ 0.5
~ 0.16
1-day exposure (30 degree off-axis, 100 MeV)
~ cm2 sec
~ (1-2) 107 cm2 sec
Attitude
fixed
variable

7. ~1 day livetime for any source
FERMI AGILE

8. ~1 day livetime for any source
FERMI AGILE

9. AGILE, Galactic Center Region at 100 and 400 MeV
E >100 MeV
E >400 MeV

10. E >100 MeV
E > 1 GeV

11. Example of the Super-AGILE View of the Galactic Plane (3
Example of the Super-AGILE View of the Galactic Plane (3.6 days, l=337, b=8)

12. Galactic Center as seen by SuperAGILE
Ginga
Sco X-1
GX 17+2
AX J
GX 5-1 4U
GRS
Daily variability in the Galactic Center
Ginga 4U
GX 17+2
GRS
Sco X-1
GX 1+4
9 Days Integration

13. Galactic sources: main topics and discoveries
10 new Pulsars
Discovery of new gamma-ray sources and gamma-ray transients in the Galaxy
Microquasar studies, Gamma-ray emission from Gal. compact objects
Colliding wind systems
SNRs and origin of cosmic rays

14. AGILE Galactic gamma-ray transient candidates

15. GRID: critical issues Source confusion
Uncertainties in diffuse Galactic emission model (dark clouds, other effects…)
Particle background
Quicklook issues
“spotting” transients
efficient alerts
statistical fluctuations

16. N° Telegram
Data
Source
coordinate l b
1848
17-Nov-08
AGL J
78.3
2.1
1827
4-Nov-08
AGL J
79.44
0.85
1592
26-giu
3C 454.3
86.11
-38.18
1585
23-giu
AGL
78.31
2.05
1583
17-giu
Mrk 421
179.83
65.03
1582
W Comae
201.73
83.2
1581
16-giu
1574
12-giu
Mkn 421
1547
27-mag
Cygnus
77.9
2.6
1545
1492
28-apr
78.01
2.19
1445
27-mar
IGR J
1.55
0.51
1436
20-mar
PKS
351.28
40.13
1428
17-mar
SAX J
0.49
-0.94
1394
22-feb
Musca
312.2
-0.3
1320
04-dic
75.0
-0.4
1308
27-nov
1300
22-nov
1278
14-nov
1221
21-set
TXS
143.98
28.01
1199
31-ago
351.1
39.7
1167
02-ago
1160
27-lug

17. AGILE ATEL’s FERMI-LAT ATEL’s

20. Cygnus Region
Carina Region
Galactic Center

21. Galactic gamma-ray transients: an AGILE discovery
Cygnus region
Carina region
Crux region
AGILE observes variability and detects new transients on time scales of 1 day at flux levels of 10-6 cm-2s-1 even in crowded, high diffuse emission Galactic plane regions.
NO detectable simultaneous hard X-ray emission (F < mCrab, keV, 1-day integration)

22. AGILE surprises
NO simultaneous strong HARD X-RAY emission (no accreting micro-qso’s in strong outburst) !!!
in general, no obvious X-ray source or INTEGRAL sources
some SWIFT follow-ups: no detection, except one.
but…Eta-Car example: colliding wind binary outburst (?!)

23. Energetics… Gamma-ray luminosity above 100 MeV
L = (a few) x 1034 d2kpc erg/s
Compatible with CWB expectations
Possible new class of (non-accreting or low X-ray) sources

24. Micro-QSO studies
Cyg X-1
Cyg X-3
GRS
SS 433 ….

25. Cygnus region

30. Cyg X-3

31. AGILE and Cygnus X-3
AGILE detects several gamma-ray flares from Cygnus X-3, and also weak persistent emission above 100 MeV
very interesting correlations with radio and X-ray states
gamma-ray flares usually before radio flares

32. example: very strong radio flare of Cygnus X-3 in April 2008
Strong radio-flare reaching ~20 Jy on Apr. 18, 2008 (RATAN)
good exposure by AGILE before, during and after the radio flare, both in hard X-rays and gamma-rays
gamma-ray flare detected at the onset of the radio flare

33. very strong radio flare, presumably with jet ejection
strong gamma-ray flare
X-ray (1-10 keV) flare
Hard X-ray flux state change (Super-A monitoring)

34. Cygnus X-3 and other micro-qso’s
Encouraging prospects for gamma-ray flares from other microquasars
Long timescale multiwavelength monitoring crucial
radio, X, gamma

40. Transient in the Cygnus Region Nov 18-28, 2007
Transient, 24 Nov. 07

41. AGLJ Light Curve

42. AGLJ2022+3622 -- Possible Source Counterparts
3EG J = 1AGL J
(Roberts et al. 2002)
Pulsar Wind Nebula PSR J
No day-scale variability expected
3EG J = B (G )‏
(Halpern et al. 2001)
Blazar outside error box
MGRO J
MILAGRO TeV source
extended and diffuse
IGR J (Sguera et al. 2006)
Other

43. LSI +61°303

44. GRID Galactic anticenter observation
LSI +61°303
GRID Galactic anticenter observation

45. LSI field (all data)

46. AGILE Counts

51. Variability of LSI
E > 100 MeV with 10% systematic error on fluxes χ2 = for 23 degrees of freedom V = Pvar = NB: V < 0.5 nonvariable source 0.5 < V < 1 uncertain V > 1 variable source (McLaughlin et al. 1996)

52. Easter 2009 transient

53. Easter transient: 10-13 April 2009, 10143-10180, bin =0
Easter transient: April 2009, , bin =0.2, B16, FM, E>100 MeV

54. Easter transient: 10-13 April 2009, 10143-10180, bin =0
Easter transient: April 2009, , bin =0.2, B16, FM, E>100 MeV

55. Easter transient: 10-13 April 2009, 10143-10180, bin =0.2, B17b, FT
E > 100 MeV
E > 400 MeV

56. Conclusions
very exciting time for Galactic gamma-ray source studies, AGILE and FERMI
first detections by AGILE of Galactic transients
no hard X-ray outbursts
low flux X-ray sources
FAST alerts and follow-up multi-freq. Observations !
Archival long-baseline studies and cross-correlation

57. Cygnus X-3
April 2008
Giant radio flare of Cygnus X-3 detected by RATAN-600 radio telescope
Radio flux increasing of a factor ~103, from ~10 mJy to ~10 Jy
S.A.Trushkin et al., ATel #1483
10 Jy is typical flux for plasmoids emission !
In the same period SuperAGILE
revealed an X-ray flare

58. RATAN Obs. (S. Truskhin et al.) Apr. 13 – Apr. 27, 2008