The nature of the infrared counterpart and of the optical nebula associated with the Central Compact Object in Vela Jr

Mignani, R. P.R. P.MignaniDE LUCA, AndreaAndreaDE LUCAZharikov, S.S.ZharikovHummel, W.W.HummelBecker, W.W.BeckerPELLIZZONI, ALBERTO PAOLOALBERTO PAOLOPELLIZZONI2020-12-232020-12-2320190035-8711http://hdl.handle.net/20.500.12386/29165The X-ray source CXO J085201.4-461753 in the few kyr-old Vela Jr. supernova remnant (SNR, G266.2-1.2) belongs to the peculiar class of isolated neutron stars dubbed `Central Compact Objects' (CCOs). At variance with the other CCOs, which are only detected in the X-rays, CXO J085201.4-461753 has been possibly detected also at other wavelengths. In particular, a candidate near-infrared counterpart (H = 21.6 ± 0.1) was detected by the Very Large Telescope (VLT) in addition to a 6 arcsec-wide nebula detected in Hα, interpreted as a velocity-driven bow shock. Here, we present new near-infrared and optical VLT observations of the candidate counterpart to CXO J085201.4-461753 and its nebula to confirm the proposed associations. Moreover, we used archival Chandra observations to measure for the first time the CXO J085201.4-461753 proper motion. The comparison between the two sets of near-infrared VLT images, taken 10.56 yr apart, do not show evidence of proper motion for the candidate counterpart to CXO J085201.4-461753, expected from its 4 arcmin offset from the SNR geometrical centre, with a 3σ upper limit of ∼10 mas yr-1. This is much smaller than the expected proper motion of ∼50-100 mas yr-1, which, in turn, is below the 3σ upper limit of ∼300 mas yr-1 that we obtained with Chandra. At the same time, VLT spectroscopy resolved the nebula optical emission, which is dominated by the N II doublet at 6548 and 6584 Å and not by Hα. To summarize, we conclude that the proposed near-infrared counterpart is likely unassociated with CXO J085201.4-461753 and that the nebula is not a velocity-driven bow shock.STAMPAenThe nature of the infrared counterpart and of the optical nebula associated with the Central Compact Object in Vela JrArticle10.1093/mnras/stz11952-s2.0-85067978610000474908200097https://academic.oup.com/mnras/article-abstract/486/4/5716/5484906?redirectedFrom=fulltext2019MNRAS.486.5716MFIS/05 - ASTRONOMIA E ASTROFISICA