The PSR J1124-5916 wind nebula in the near-infrared^⋆

¹ Instituto de Astronomía, Universidad Nacional Autónoma de México, Ensenada, Mexico
e-mail: zhar@astrosen.unam.mx
² Ioffe Physical Technical Institute, Politekhnicheskaya 26, 194021 St. Petersburg, Russia
e-mail: dima_zyuz@mail.ru
³ St. Petersburg State Polytechnical Univ., Politekhnicheskaya 29, 195251 St. Petersburg, Russia
e-mail: shib@astro.ioffe.ru
⁴ Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
e-mail: rmennick@astro-udec.cl

Received: 12 February 2013
Accepted: 29 April 2013

Abstract

Context. The young radio pulsar J1124-5916 is associated with the Cas A like supernova remnant G292.0+1.8. It powers a compact torus-like pulsar wind nebula with a jet first detected in X-rays and then identified in the optical and mid-infrared.

Aims. We carried out deep near-infrared observations of the pulsar field to identify the pulsar and its nebula in this range.

Methods. The direct-imaging mode of the NACO adaptive optics instrument at the ESO VLT in the H and K_s bands was used.

Results. We detected a faint, H = 21.30(10) and K_s = 20.45(10), extended elliptical object in both bands, whose center position is consistent with the X-ray position of the pulsar. The morphology of the object and the orientation of its major axis agree well with those observed for the pulsar torus-like nebula in the mid-infrared, optical, and X-rays. This suggests that it is the near-infrared counterpart of the nebula. The measured fluxes compiled with the data in other ranges show a complicated unabsorbed power-law spectrum of the torus-like nebula with several steep breaks between the near-infrared and mid-infrared, the optical and X-rays, and possibly in the mid-infrared. This implies a multiple relativistic particle population responsible for the synchrotron emission of the nebula in different spectral ranges. We have not resolved the pulsar counterpart from its nebula and place only upper limits on its brightness, H ≥ 23.9 and K_s ≥ 22.7. Based on that, its contribution to the total near-infrared flux of the pulsar+nebula system is ≤ 10%, which is comparable with the expected contribution in the optical.