- high |b|, non pulsar LAT bright source are associated to radio sources - 98/106 (92%) in LBAS have 8.4 GHz flux density > 100 mJy - Log of radio luminosity is 39.0 < Log Lr < 45.3 [erg s^-1]
- radio luminosity distribution is different for BL Lacs and FSRQ:
- Log Lr, BLL = 42.8 +/- 1.1 [erg s^-1]
- Log Lr, FSRQ = 44.4 +/- 0.6 [erg s^-1]
- RG: NGC 1275 similar to BL Lacs (Log Lr = 42.2 [erg s^-1]), Cen A much less luminous (Log Lr = 39.1 [erg s^-1])
- 8.4 GHz data are representative of radio flux density in general - negligible extended emission - flat spectrum compact cores, overluminous with respect to radio galaxies (except Cen A)
- We have already a significant improvement over EGRET numbers, so we want to address the existence of actual correlation between radio and gamma ray properites. There's a number of bias/effects that we have to keep in mind, so we tried to look into different pairs of quantities
- when we have z, we calculate luminosity and K-correct - else we just use S_8.4 and F_>100 MeV
- BL Lacs and FSRQ tend to populate different regions, so we make correlation analysis for full population and single classes separately
- Spearman rank is used - partial analysis is used as far as luminosity are concerned
Data |
Class |
n. sources |
Correlation coeff. |
Chance probability |
|---|---|---|---|---|
S_8.4-F_>100 MeV, mean |
All |
106 |
0.44 |
0.000001 |
S_8.4-F_>100 MeV, peak |
All |
106 |
0.38 |
0.000027 |
Log L_r-Log L_gamma |
All |
88 |
0.48 |
0.000001 |
S_8.4-F_>100 MeV, mean |
FSRQ |
57 |
0.22 |
0.050 |
S_8.4-F_>100 MeV, peak |
FSRQ |
57 |
0.21 |
0.064 |
Log L_r-Log L_\gamma |
FSRQ |
57 |
0.38 |
0.0021 |
S_8.4-F_>100 MeV, mean |
BL Lacs |
42 |
0.51 |
0.00036 |
S_8.4-F_>100 MeV, peak |
BL Lacs |
42 |
0.41 |
0.0039 |
Log L_r-Log L_gamma |
BL Lacs |
30 |
0.53 |
0.0013 |
- peak gamma-ray flux and mean radio flux: hints of a weak correlation, but significativity is not so strong - even more when BL Lacs and FSRQ are considered separately
- gamma-ray index and radio luminosity: the large energy band of LAT shows a clear difference in gamma-ray index for BL Lacs and FSRQ and this is apparent also in this diagram. Some outliers are also easy to spot: a radio galaxy (Cen A), a low energy peaked/low luminosity FSRQ, PMN J0948+0022