Optical photometry of the PSR B0656+14 and its neighborhood

¹ Ioffe Physical Technical Institute, Politekhnicheskaya 26, St. Petersburg 194021, Russia e-mail: shib@stella.ioffe.rssi.ru
² The Pennsylvania State University, Department of Astronomy & Astrophysics, 525 Davey Lab, University Park, PA 16802, USA e-mail: pavlov@astro.psu.edu
³ Special Astrophysical Observatory of RAS, Karachai-Cherkessia, Nizhnij Arkhyz 357147, Russia e-mail: sokolov@sao.ru
⁴ Observatorio Astronomico Nacional de Instituto de Astronomia de UNAM, Ensenada, B.C., 22860, Mexico e-mail: zhar@astrosen.unam.mx
⁵ Astro Space Center of the Russian Academy of Sciences, Moscow 117810, Russia e-mail: vkurt@asc.rssi.ru

Corresponding author: A. B. Koptsevich, kopts@astro.ioffe.rssi.ru

Received: 25 July 2000
Accepted: 22 February 2001

Abstract

We present the results of broad-band photometry of the nearby middle-aged radio pulsar PSR B0656+14 and its neighborhood obtained with the 6-meter telescope of the SAO RAS and with the Hubble Space Telescope. The broad-band spectral flux of the pulsar decreases with increasing frequency in the near-IR range and increases with frequency in the near-UV range. The increase towards UV can be naturally interpreted as the Rayleigh-Jeans tail of the soft thermal component of the X-ray spectrum emitted from the surface of the cooling neutron star. Continuation of the power-law component, which dominates in the high-energy tail of the X-ray spectrum, to the IR-optical-UV frequencies is consistent with the observed fluxes. This suggests that the non-thermal pulsar radiation may be of the same origin in a broad frequency range from IR to hard X-rays. We also studied 4 objects detected within 5´´from the pulsar.