Optical Identification Of Un

Optical Identification Of Un-ID
Fermi Gamma Ray Sources
Chia-Jung Chuang (NCU)
Supervisor : Yuji Urata (NCU)
2011年8月5日金曜日
Aim
Aim : Identified Blazar/AGN from 1FGL at
extragalactic
• AGN Unified model - Beam effect
•
Identified un-ID objects can help us to
understand gamma ray process for extragalactic
sources.
•
Some normal galaxies -- NGC 1275 (Abdo et al.
2009 ApJ), starburst galaxies NGC 253 and M82
(Abdo et al. 2010 ApJL) and normal QSOs -PMN J0948+0022 (Abdo et al. 2009 ApJ)
emitted gamma ray (MeV to GeV).
DʼAmmando et al. 2011
2011年8月5日金曜日
AGN Unified model
NGC 1275 HST image
NGC 1275
Fermi gamma
ray image
PMN J0948+0022 Fermi
gamma ray image
Method
2011年8月5日金曜日
•
Fermi 1FGL catalog (target selection)
•
X-ray - Swift/XRT ( identification of X-ray sources)
•
Optical
•
Color-color (SDSS, LOT, Pan-STARRs) : excluding
stellar like objects
•
Variability (LOT, PTF) : excluding variable stars
Target selection
•
Fermi First Year Catalog (1FGL) :
•
First 11 months science operation (2008/08~2009/07)
•
1451 sources detected by the LAT (Energy range : 100 MeV to 100
GeV)
•
630 un-identification sources
Selection :
- High galactic latitude (> |30| deg)
- Dec > -30 deg (for ground based
optical observations with PanSTARRS, LOT, SDSS)
15 sources are selected.
The 1451 1FGL catalog sources, in Galactic coordinate. Gray : unassociated sources, Blue : associated sources and Red : =irmly identi=ied sources (primarily pulsars)
2011年8月5日金曜日
X-ray
•
•
Swift/XRT - 0.3 to 10 keV
•
•
•
Pros : Position error is smaller than gamma-ray
13 sources have Swift observation (we have already
reduced all.). 6 fields have detection.
Pros : Numbers of detections are less than optical.
Cons: Tend to be poor S/N (no spectral information)
1FGL J1511.8-0513
2011年8月5日金曜日
1FGL J0439.8-1857
1FGL J1312.6+0048
Optical
•
SDSS (DR8) : Multi-color (ugriz)
•
Pan-STARRS : 3PI wide field surveys (wider & deeper than SDSS with
grizY)
•
PTF : higher cadence with other surveys & long-term monitoring.
•
Lulin One-meter Telescope in Taiwan (flexible obs with Ugriz)
•
Pros : Wide sky coverage (SDSS &
Pan-STARRS)can be hunt everything
visible in northern sky!
Pros : Repeating/Monitoring
•
observations (Pan-STARRS, LOT)
Cons : Too much detections
•
Pan-STARRS 1year sky coverage (all bands)
→ Color-color diagram & variability
2011年8月5日金曜日
Optical
•
SDSS (DR8) : Multi-color (ugriz)
•
Pan-STARRS : 3PI wide field surveys (wider & deeper than SDSS with
grizY)
•
PTF : higher cadence with other surveys & long-term monitoring.
•
Lulin One-meter Telescope in Taiwan (flexible obs with Ugriz)
•
Pros : Wide sky coverage (SDSS &
Pan-STARRS)can be hunt everything
visible in northern sky!
Pros : Repeating/Monitoring
•
observations (Pan-STARRS, LOT)
Cons : Too much detections
•
Pan-STARRS 1year sky coverage (all bands)
→ Color-color diagram & variability
2011年8月5日金曜日
Color-color diagram
•
Select “blue” type for QSOs and Blazars from color-color diagram.
•
Exclude typical stellar type objects
•
Use SDSS-DR8, Lulin/LOT (1m) and Pan-STARRs data
Stars
QSOs
Color-color plots of 3040 SDSS quasars. Colors are
indicative of their redshift
Richards et al. 2002
2011年8月5日金曜日
Variability
•
Relativistic jet of Blazar/AGN
produce rapid variability.
•
Variability ~ several days
•
High cadence optical
observations (with LOT & PTF)
D’Ammando et al. 2011
2011年8月5日金曜日
Results
2011年8月5日金曜日
1FGL J1254.4+2209
- 12:54:28.6 +22:09:00 error radius : 0.09 deg
- two X-ray sources
- one IR source
- LOT observation 2011 2/4,5,6, 4/13,19,21
- PTF 9 epochs with R-band
- Source 1 X-ray and IR(AKARI) source
Optical -> bright star
- Source 2 X-ray source
with optical counterpart (r~17 mag)
SDSS classified as star but outlier of
the color trend of stars
Joint LOT/PTF LC show variabilities
Swift/XRT(0.5-10keV)
LOT(r)
Source 2 has strong possibilities to be the Fermi/unID counterpart as AGN/Blazar.
Optical color-color diagram to exclude normal stars based on SDSS(DR8).
The pink circles indicate the optical counterpart of source2.
Joint LOT (r, i) and PTF (R) light curves.
2011年8月5日金曜日
1FGL
J1258.3+2125
- 12:58:21.0 +21:25:15 error radius : 0.10 deg
- have no 2FGL detection
- two X-ray sources
- LOT observation 2011 2/4,5,6, 4/13
- Source 1 : X-ray source - stable
- Source 2 : X-ray source have obvious
variability in our time coverage
- Source 3 (red circle) : strange color star ->
variability(PTF) (~13 mag).
- Source 4 : galaxy 1 - stable
- Source 5 : galaxy 2 - variability(PTF) (~12
mag)
- Source 6 : galaxy 3 - not so clear (need to add
epochs)
Swift/XRT(0.5-10keV)
Optical color-color diagram to exclude normal stars based on SDSS(DR8).
2011年8月5日金曜日
LOT(r)
1FGL J1258.3+2125
Joint LOT (r) light curves.
Joint PTF (R) light curves.
2011年8月5日金曜日
1FGL J1040.5+0616
- 10:40:30.5 +06:16:39 error radius : 0.12 deg
- four X-ray sources
- LOT observation 2011 2/4,5,6,7, 4/13,21
- nearby and associated with 4C +06.41, but
out region
- Target 4 X-ray source - too faint
with optical counterpart (r ~ 20.7 mag)
- Target10 X-ray source - stable
with optical counterpart (r~19.6 mag)
- Target12 X-ray source - variability
with optical counterpart (r~18.6 mag)
- Target13 X-ray source - variability
with optical counterpart (r~19.8 mag)
- Three strange color star red circle
all saturated in LOT data.
- Galaxy 1 - variability
- Galaxy 2 - saturated
- Galaxy 3 - stable
- Galaxy 4 - variability
- Galaxy 5 - stable
Swift/XRT(0.5-10keV)
Optical color-color diagram to exclude normal stars based on SDSS(DR8).
2011年8月5日金曜日
LOT(r)
1FGL J1040.5+0616
Joint LOT (r) light curves.
2011年8月5日金曜日
Summery
•We selected 15 targets, some of them
have X-ray detection and some of them
not.
•Many sources have both strange color and
variability in the same field.
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Future work
• Extend optical observation epochs for
each frame
• Make SED fitting
• Gamma ray analysis
2011年8月5日金曜日
The End
2011年8月5日金曜日

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