Prospects for IXPE and eXTP polarimetric archaeology of the reflection nebulae in the Galactic Center. (arXiv:2008.07830v2 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Gesu_L/0/1/0/all/0/1">L. Di Gesu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ferrazzoli_R/0/1/0/all/0/1">R. Ferrazzoli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Donnarumma_I/0/1/0/all/0/1">I. Donnarumma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soffitta_P/0/1/0/all/0/1">P. Soffitta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Costa_E/0/1/0/all/0/1">E. Costa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Muleri_F/0/1/0/all/0/1">F. Muleri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pesce_Rollins_M/0/1/0/all/0/1">M. Pesce-Rollins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marin_F/0/1/0/all/0/1">F. Marin</a>
The X-ray polarization of the reflection nebulae in the Galactic Center
inform us about the direction of the illuminating source (through the
polarization angle) and the cloud position along the line of sight (through the
polarization degree). However, the detected polarization degree is expected to
be lowered because of the mixing of the emission of the clouds with the
unpolarized diffuse emission in the GC region. In addition, in a real
observation, also the morphological smearing of the source due to the PSF and
the unpolarized instrumental background contribute in diluting the polarization
degree. So far, these effects have never been included in the estimation of the
dilution. Here, we evaluate the detectability of the X-ray polarization
predicted for the MC2, Bridge-B2, G0.11-0.11, Sgr B2, Sgr C1, Sgr C2 and Sgr C3
molecular clouds with modern X-ray imaging polarimeters like the Imaging X-ray
Polarimetry Explorer (IXPE) and the Enhanced X-ray Timing and Polarimetry
mission (eXTP). We perform realistic simulations of X-ray polarimetric
observations considering (with the aid of Chandra maps and spectra) the
spatial, spectral and polarization properties of all the diffuse emission and
background components in each region of interest. We find that in the 4.0$-$8.0
keV band, where the emission of the molecular clouds outshines the other
components, the dilution of the polarization degree, including the contribution
due to the morphological smearing of the source, ranges between $sim$19% and
$sim$55%. We conclude that, for some values of distances reported in the
literature, the diluted polarization degree of G0.11-0.11, Sgr B2, Bridge-B2,
Bridge-E, Sgr C1 and Sgr C3, may be detectable in a 2 Ms long IXPE
observations. The enhanced capabilities of eXTP may allow to detect the
4.0$-$8.0 keV of all the targets considered here.
The X-ray polarization of the reflection nebulae in the Galactic Center
inform us about the direction of the illuminating source (through the
polarization angle) and the cloud position along the line of sight (through the
polarization degree). However, the detected polarization degree is expected to
be lowered because of the mixing of the emission of the clouds with the
unpolarized diffuse emission in the GC region. In addition, in a real
observation, also the morphological smearing of the source due to the PSF and
the unpolarized instrumental background contribute in diluting the polarization
degree. So far, these effects have never been included in the estimation of the
dilution. Here, we evaluate the detectability of the X-ray polarization
predicted for the MC2, Bridge-B2, G0.11-0.11, Sgr B2, Sgr C1, Sgr C2 and Sgr C3
molecular clouds with modern X-ray imaging polarimeters like the Imaging X-ray
Polarimetry Explorer (IXPE) and the Enhanced X-ray Timing and Polarimetry
mission (eXTP). We perform realistic simulations of X-ray polarimetric
observations considering (with the aid of Chandra maps and spectra) the
spatial, spectral and polarization properties of all the diffuse emission and
background components in each region of interest. We find that in the 4.0$-$8.0
keV band, where the emission of the molecular clouds outshines the other
components, the dilution of the polarization degree, including the contribution
due to the morphological smearing of the source, ranges between $sim$19% and
$sim$55%. We conclude that, for some values of distances reported in the
literature, the diluted polarization degree of G0.11-0.11, Sgr B2, Bridge-B2,
Bridge-E, Sgr C1 and Sgr C3, may be detectable in a 2 Ms long IXPE
observations. The enhanced capabilities of eXTP may allow to detect the
4.0$-$8.0 keV of all the targets considered here.
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