Refined X-ray position and near-IR identification for IGR J16413-4046
ATel #3342; John A. Tomsick (SSL/UC Berkeley), Sylvain Chaty (AIM - Univ. Paris 7 and CEA Saclay), Arash Bodaghee (SSL/UC Berkeley), Jerome Rodriguez (CEA-SAp/Lab. AIM Saclay)
on 12 May 2011; 17:09 UT
Credential Certification: John A. Tomsick (jtomsick@ssl.berkeley.edu)
Subjects: Infra-Red, X-ray, Black Hole, Neutron Star
IGR J16413-4046 is a hard X-ray source first reported in the
4th IBIS/ISGRI catalog (Bird et al. 2010). Follow-up Swift/XRT
observations found an X-ray source with a hard X-ray spectrum
within the INTEGRAL error circle that was identified as the
counterpart to the IGR source (Landi et al. 2010, ATEL#2731;
Landi et al. 2011, ATEL#3178).
As part of our Chandra program to localize sources discovered by
INTEGRAL in the Galactic Plane, we obtained a 5.0 ks ACIS exposure
of the IGR J16413-4046 field on UT 2011 May 9, 0.5-2.3 h. The
brightest Chandra source in the field is CXOU J164119.4-404737,
which has a position that is consistent with the position of
the Swift source. The exact Chandra position of this source
is R.A. = 16h 41m 19s.49, Decl. = -40d 47' 37".8 (equinox 2000.0,
90% confidence uncertainty = 0".64). This is consistent with
the position of 2MASS J16411948-4047378, which has near-IR
magnitudes of H = 15.08 +/- 0.11 and Ks = 13.97 +/- 0.07. This
source is not present in the DENIS near-IR/optical or USNO optical
catalogs. Also, we note that 2MASS J16411948-4047378 is not the
2MASS source that was originally suggested to be the near-IR
counterpart in ATEL#
2731. That source, 2MASS J16411927-4047323,
is 6" from the Chandra position and, thus, is not the counterpart.
We plan to present a more detailed analysis of the Chandra
data in a forthcoming paper. We encourage follow-up near-IR
and optical observations of the source to determine its nature.
