1 / 7

SPASE point source search

SPASE point source search. Look for ~100 TeV gamma-rays from 3 specific HESS sources high in the southern sky. Three HESS sources. Shell-type SNR RX J0852.0-4622 ( q =43.8 o ) differential G = 2.1 ± 0.1; E g ,max > 10 TeV F(>TeV) = 1.9 x 10 -11 cm -2 s -1 (astro-ph/0505380)

iliana-schmidt
Download Presentation

SPASE point source search

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SPASE point source search Look for ~100 TeV gamma-rays from 3 specific HESS sources high in the southern sky

  2. Three HESS sources • Shell-type SNR RX J0852.0-4622 (q=43.8o) • differential G = 2.1 ± 0.1; Eg,max > 10 TeV • F(>TeV) = 1.9 x 10-11 cm-2s-1 (astro-ph/0505380) • Pulsar wind nebula MSH 15-52 (q=38o) • G = 2.27 ± 0.20; Eg,max > 30 TeV • F(>TeV) = 4.5 x 10-12 cm-2s-1 (astro-ph/0504120) • Unidentified HESS J1303-631 (q=26.9o) • G = 2.44 ± 0.2; Eg,max > 10 TeV • F(>TeV) = 3.0 x 10-12 cm-2s-1 (A&A 439, 2005, 1013)

  3. Sensitivity of SPASE • S30 (fitted density at 30 m from fitted core) is proxy for Energy. For protons • E ~ 50 TeV (S30)0.9 (E ~ 100 TeV at S30 ~2.2) • Median S30 ~ 2.5 corresponds to E ~ 115 TeV for near vertical events • Angular resolution • ~3o for S30 < 2 • ~2o for S30 > 2, plus response more stable, but energy threshold higher

  4. Sensitivity of SPASE (cont.) • Angular response: • dN / dcos(q) ~ exp[ - 7 x (sec(q) – 1)] • due to attenuation at greater slant depth • implies relation for attenuation of S30 • dN / d S30 ~ exp[ - ( X(q) – X(0)) / 160 g/cm2 ) • Energy response: • Threshold energy increases with angle • SPASE-1 search  Eth ~ 50, 100, 200 TeV • for q = 26.9o, 38o, 43.8o, respectively • (see J. van Stekelenborg et al., PRD48(1993) 4504 )

  5. Sensitivity of SPASE (cont.) • Exposure: ~104 m2 x 3 live yrs ~1016 cm2s • Multiply by cos(q) (projected area) • Background: 2 x 108, from all directions • Look at 3o x 3o, all events; 2o x 2o, S30 > 2 • Background/bin: 3 x 105, 1.6 x 105, 8 x 104for q = 26.9o, 38o, 43.8o, respectively, for all evnts • Background/bin: 7 x104, 3.4 x 104, 1.8 x 104for q = 26.9o, 38o, 43.8o, respectively, for S30 > 2

  6. Expected signal all events, 3o x 3o search bin, assuming no cutoff • SNR RX J0852.0-4622 (q=43.8o) • F(>200 TeV) ~ 6 x 10-14 cm-2 s-1 • 400 signal / 8 x104 background (1.5 s) • PWN MSH 15-52 (q=38o) • F(>100 TeV) ~ 1.3 x 10-14 cm-2s-1 • 100 signal / 1.6 x105 background (0.25 s) • Un-ID J1303-631 (q=26.9o) • F(>50 TeV) ~ 1.1 x 10-14 cm-2s-1 • 100 signal / 3 x105 background (0.2 s)

  7. Expected signal all events, 2o x 2o search bin, assuming no cutoff • SNR RX J0852.0-4622 (q=43.8o) • F(>400 TeV) ~ 2.8 x 10-14 cm-2 s-1 • 200 signal / 1.8 x104 background (1.5 s) • PWN MSH 15-52 (q=38o) • F(>200 TeV) ~ 5 x 10-15 cm-2s-1 • 45 signal / 3.4 x104 background (0.25 s) • Un-ID J1303-631 (q=26.9o) • F(>100 TeV) ~ 4 x 10-15 cm-2s-1 • 36 signal / 1.8 x104 background (0.25 s)

More Related