H.E.S.S. unidentified sources: how can Fermi GST...

H.E.S.S. unidentified H.E.S.S. unidentified sources: how can Fermi sources: how can Fermi

GST help?GST help?

66thth Workshop on Science with the New Generation Workshop on Science with the New Generation

of High Energy Gamma-Ray Experimentsof High Energy Gamma-Ray Experiments

88thth-10-10thth of October 2008 Padova, Italy of October 2008 Padova, Italy

Omar TibollaOmar Tibolla (Landessternwarte, Heidelberg University, and(Landessternwarte, Heidelberg University, and

Max Planck Institute for Nuclear Physics)Max Planck Institute for Nuclear Physics)

on behalf of theon behalf of the H.E.S.S CollaborationH.E.S.S Collaboration

Introduction

Omar Tibolla SciNeGHE 08. Padova, 8th-10th of October 2008

The VHE (>1012 eV) sources generally show X-ray counterparts (the same population of e- emits via Synchrotron and via IC? Secondary e- from hadronic processes, pions decay?) But what is the correlation between TeV and GeV -rays?

J. Hinton et al., A&A 476, L25 (2007)

GeV Status


GeV Status: somebody new...

Fermi GST First Light (released the 26th of August): 4 days of data.In a few of days, GLAST has corroborated many of the great discoveries of EGRET and AGILE, finding new sources as well.

(now we have more than 3 months of data...)


TeV status


TeV status: H.E.S.S. Survey


H.E.S.S. vs EGRET

S.Funk et al., ApJ 679, 1299 (2008)

They took the first H.E.S.S. Galactic plane survey (Aharonian et al., ApJ, 636 (2006), 777) and compared it with the 3rd EGRET Catalog (Hartman et al., ApJS, 123 (1999), 79).

But of the case of 3EG J1714-3857 and of the GC, they found:

(17 3EG sources within the H.E.S.S. GPS region)


Note: TeV vs GeV

Outside the H.E.S.S. Galactic Plane Survey there are other 4 TeV Galactic sources that are spatially coincident with 4 3EG sources:

- LSI +61 303: MAGIC J0240+613 is within the 99% positional uncertainty contour of 3EG J0241+6103.

- IC443: MAGIC J0616+225 is within the 99% positional uncertainty contour of 3EG J0617+2238.

- Monoceros: HESS J0632+058 is within the 99% positional uncertainty contour of 3EG J0634+0521.

- Kookaburra: HESS J1420+607 is within the 68% positional uncertainty contour of 3EG J1420+6038.

But it seems that generally VHE sources do not coincide with 3EG ones.(However the few sources that coincide generally show spectral match)


Is it time to join GeV and TeV?


What can Fermi GST do?

LAT specifications and performances are much better than EGRET's ones:

And moreover EGRET was unable to perform detailed studies above 10 GeV, because of the self-veto due to calorimeter back-splash (LAT ACD is instead segmented)


important achievements

Thanks to its better performances, Fermi GST will be able to:- solve the instrumental mismatch that we see in the energy flux distribution of EGRET and H.E.S.S. Sources.- distinguish between hadronic and leptonic scenarios.

S.Funk et al., ApJ 679, 1299 (2008)


H.E.S.S. Survey extension

In the meaning while H.E.S.S., in 2006/2007, extended the very successful VHE Galactic survey of 2004/2005, discovering a number of new sources, many of whichare unidentified. Actually H.E.S.S. detected over 50 Galactic sources.

Recently (announced at Gamma 08 Symposium):- CTB 37B- CTB 37A- RCW 86- HESS J1356-654 (candidate offset PWN, coincident with an old plerion)- HESS J1503-582 (coincident with a Forbidden Velocity Wing)- HESS J1848-018 (SFR W43, WR 121a)- HESS J1849-000 (PWN)- Kes 75- SN 1006...but let's concentrate to the unidentified H.E.S.S. sources...


H.E.S.S. new unidentified sources

HESS J1427−608 HESS J1626−490 HESS J1702−420HESS J1708−410HESS J1731−347 HESS J1841−055 HESS J1857+026 HESS J1858+020

(A&A 477 (2008) 353-363)

HESS J1745-303

(A&A 483 (2008) 509-517)

HESS J1741-302

(Gamma 08)


HESS J1427-608

1o away from G313.2+0.3(hard X-ray and GeV-ray source in the Kookaburra region). 5.6 in 21 hours of observation.Spectrum fits well with a PL with index ~2.2.In the right panel Radio (Molonglo survey) data and X-ray (RAS) contours in green.


HESS J1626-490

6 in 8 hours of observation.Spectrum fits well with a PL with index ~2.2.Labeled with an “X” in the left panel, the unidentified X-ray source 1RXS J162504-490918, possible counterpart.


HESS J1702-420

10.6 in 7 hours of observation.Spectrum fits well with a PL with index ~2.1.PSR J1702-4128 (spin-down luminosity 1.3 ∙ 1034 erg/s kpc2) provides enough spin-down energy loss to produce the observed emission. Offset PWN?There are also a SNR (small in angular size and distant) and 3 XRB.


HESS J1708-410

10.3 in 45 hours of observation.Spectrum fits well with a PL with index ~2.5.In the FoV: 1RXS J171011.5-405356, the SNR G345.7-00.2 and the XRB 4U 1708-40; no plausible counterparts.


HESS J1731-347

8.3 in 11 hours of observation.Spectrum fits well with a PL with index ~2.3.X1 is 1RXS J173251.1-344728, R is the radio point source 173028-344144 and X2 is the bright 1RXS J173030.3-343219.Recently an identification with a SNR has been proposed (!).


HESS J1841-055

10.7 in 10 hours of observation.Spectrum fits well with a PL with index ~2.4.2 SNRs: Kes 73 (G027.4+00.0) and G26.6-0.1; 3 Pulsars: PSR J1841-0524 (spin-down luminosity 4.4 ∙ 1033 erg/s kpc2), PSR J1838-0549 (spin-down luminosity 4.7 ∙ 1033 erg/s kpc2) and PSR J1837-0604 (spin-down luminosity 5.2 ∙ 1034 erg/s kpc2); and AX J1841.0-0586 (a possible XRB).


HESS J1857+026 and HESS J1858+020

HESS J1857+026 (recently an identification with a PWN has been proposed):10.2 in 15 hours of observation.Spectrum fits well with a PL with index ~2.4.

HESS J1858+020:7.4 in 23 hours of observation.Spectrum fits well with a PL with index ~2.2.(X is 1RXS J185608+0218) No plausible counterparts.


Can Fermi GST detect them?

Ignoring the Galactic Plane (crucial point at GeV energies)...

OK OK?

OK?NO?


NO

OK?

OK?

OK?


Can Fermi GST detect them? (2)

HESS J1745-303(Galactic Center region)

12 in 79 hours of observation. Spectral index (total) is ~2.7; ~2.7 (A), ~2.9 (B) and ~2.9 (C).HESS J1745-303 (mentioned in slide 7) is one of the most interesting new H.E.S.S. Sources and it is spatially coincident with 3EG 1744-3011.G359.1-0.5 and Molecular Clouds (T.Dame catalog) coincident with the hot spot A.PSR B1742-30 (spin-down luminosity 2 ∙ 1033 erg/s kpc2), PSR J1747-2958 (spin-down luminosity 4 ∙ 1035 erg/s kpc2) and the ultra compact XRB SLX 1744-300.


Ri ght Ascensi on

Decl

inat

ion

3 0 '°- 3 0

0 0 '°- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0

4 0

5 0

PSR J1739- 3023

PSR J1741- 3016PSR B1737- 30

Excess, accept ance- correct ed

m4 0h1 7m4 1h1 7m4 2h1 7m4 3h1 7Ri ght Ascensi on

Decl

inat

ion

3 0 '°- 3 0

0 0 '°- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

PSR J1739- 3023

PSR J1741- 3016PSR B1737- 30

Uncorrel at ed Sky Excess Map

m4 0h1 7m4 1h1 7m4 2h1 7m4 3h1 7

HESS J1741-302(Galactic Center region)

Newly discovered. Discovery announced in Gamma 08 Symposium.In a region extremely rich of Molecular Clouds.Or a PWN??Multiwavelength campaign started (Chandra, NANTEN).

Ri ght Ascensi on

Declination

30 '°- 3 1

00 '°- 3 1

30 '°- 3 0

00 '°- 3 0

30 '°- 2 9

00 '°- 2 9

- 6

- 4

- 2

0

2

4

6

8

Sky Si gni f i cance Map

m3 5h1 7m4 0h1 7m4 5h1 7


Conclusion...

Be patient and wait for Fermi GST... in order to see closing the gap between keV and TeV...


Thanks for Thanks for your attention!your attention!

Spare SlidesSpare Slides

H.E.S.S. Survey


Slice (for J1745)

A slice along RA (visible in the excess map) across the region indicates two structures; the excess counts in the slice are fitted with:- Gaussian distribution (in red, χ2/d.o.f.=30.18/17) - a double Gaussian distribution (in green, χ2/d.o.f.=10.24/14).


Slice for the 2 hot spots

The slice connecting the two hotspots is fitted with:- a Gaussian distribution (in red, χ2/d.o.f.=15.82/17) - with a double Gaussian distribution (in green, χ2/d.o.f.=5.95/14). We are not allowed to do detailed statements about source morphology.


...we claimed the detection...

...at Gamma 08 Symposium...and soon we'd like to publish it


Ri ght Ascensi on

Decl

inat

ion

3 0 '°- 3 0

0 0 '°- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0

4 0

5 0

PSR J1739- 3023

PSR J1741- 3016PSR B1737- 30

Excess, accept ance- correct ed

m4 0h1 7m4 1h1 7m4 2h1 7m4 3h1 7Ri ght Ascensi on

Decl

inat

ion

3 0 '°- 3 0

0 0 '°- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

PSR J1739- 3023

PSR J1741- 3016PSR B1737- 30

Uncorrel at ed Sky Excess Map

m4 0h1 7m4 1h1 7m4 2h1 7m4 3h1 7

Reminder “Counterparts”

No clear counterpart: Molecular Clouds (1) or PWN (2).. -PSR B1737-30, spin-down luminosity: 7.7 ∙ 1033 erg/s kpc2 -PSR J1741-3016, spatially coincident: 2.1 ∙ 1030 erg/s kpc2 (but 4-5 order of magnitude weaker in spin-down luminosity than what we would expect to see at TeV energies)


H.E.S.S. unidentified sources: how can Fermi GST...

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