IGR J18135-1751

Other name = HESS J1813-178, AX J1813-178, G12.82-0.02, (AGPS 273.4-17.8 ?), CXOU J181335.1-174957

Type Mass Radio Counterpart Infrared/Optical Counterpart
R.A. (J2000) Dec. (J2000) References R.A. (J2000) Dec. (J2000) References
Composite SNR, PWN + radio shell
Miscellaneous :

Ubertini et al. 2005:
  • NH~5 x 1022 cm-2
  • photon index=1.8
  • extended radio counterpart candidate
  • 20-100 keV luminosity of 5.7 1034 erg/s (if located at 4 kpc)
Funk et al. 2007:
  • Presence of a giant molecular cloud in the vicinity of the high energy source => exclude a relation of this cloud to the high energy source, although it may have influenced its evolution in the past.
  • XMM => Compact core with an extended tail at a position coincident with the ASCA source.
  • Extension is estimated to be 21" in size.
  • XMM => Absorbed power law like spectrum with Nh=1e23 cm-2 and Gamma=1.8
  • X-ray images & VLA images => source is a probable composite SNR composed of a PWN (the compact X-ray source) in a shell like radio structure.
  • Origin of the very high energy emission either from the compact X-ray source or the shell of the SNR
Helfand et al. 2007:
  • With Chandra resolve X-ray emission into emission from a point source surrounded by structure diffuse emission
  • Refined position of the pulsar is RA= 18h 13m 35.166s, Dec= -17o 49' 57.48" ± 0.3 " at 1 sigma, (CXOU J181335.1-174957)
  • Both the PWN and the pulsar spectra are well fitted with a power law of similar index Gamma=1.3. NH9.8e22 cm-2
  • 3-sigma upper limit of 27% on a pulse for period greater than 6.5 s.
  • Remnant asociated to the high energy source (G12.82-0.02) <=> young rotation powered pulsar.
  • Estimate a dE/dt=4 e 36 erg/s.
Dean & Hill 2008:
  • Explore the possibilities for the properties of the putative pulsar
  • Assuming magnetic dipole losses, L(20-100 keV)/dot(E)=1%, age of 300 yrs, d=4.5 kpc =>extreme set of parameters: P=0.55s dot(P)=3e-11 s/s and B=1.28e14 G
  • Several possibilities explored, but either quite unlikely (d=45 kpc), or extreme (conversion eff=0.01%).
  • Most likely explanation: pulsar born with a spin not very different from actual value: spin down age should be decoupled from the actual age

Last updated. 13 june 2008

Jerome Rodriguez