N ov 2 00 8 A variable near - infrared counterpart to the neutron - star low - mass X - ray binary 4 U 1705 − 440 1
نویسندگان
چکیده
We report the discovery of a near-infrared (nIR) counterpart to the persistent neutron-star low-mass X-ray binary 4U 1705−440, at a location consistent with its recently determined Chandra X-ray position. The nIR source is highly variable, with Ks-band magnitudes varying between 15.2 and 17.3 and additional Jand H-band observations revealing color variations. A comparison with contemporaneous X-ray monitoring observations shows that the nIR brightness correlates well with X-ray flux and X-ray spectral state. We also find possible indications for a change in the slope of the nIR/X-ray flux relation between different X-ray states. We discuss and test various proposed mechanisms for the nIR emission from neutron-star low-mass X-ray binaries and conclude that the nIR emission in 4U 1705−440 is most likely dominated by X-ray heating of the outer accretion disk and the secondary star. Subject headings: accretion, accretion disks — binaries: close — stars: individual (4U 1705−440) — X-rays: binaries This paper includes data gathered with the 6.5 meter Magellan Baade Telescope located at Las Campanas Observatory, Chile, and the 4 meter Blanco Telescope located at CTIO, Chile. MIT Pappalardo and Hubble Fellow
منابع مشابه
ar X iv : a st ro - p h / 98 03 01 8 v 1 3 M ar 1 99 8 Discovery of Kilohertz QPOs in the Atoll X - Ray Binary 4 U 1705 - 44 Eric
In observations with the Rossi X-ray Timing Explorer we have discovered quasiperiodic oscillations (QPOs) near 1 kHz from 4U 1705-44, a low–mass X-ray binary with a neutron star classified as an atoll source. In six separate observations, we detect one QPO with a frequency ranging between 770 and 870 Hz and a 4% rms fraction in the full detector energy band. There is evidence for a second QPO a...
متن کاملThe Symbiotic Neutron Star Binary Gx 1+4/v2116 Ophiuchi
We present extensive optical, infrared, and X-ray observations of the S-type symbiotic low-mass X-ray binary GX 1+4/V2116 Oph, which consists of a 2-min X-ray pulsar accreting from an M6 III giant. This is the only symbiotic system definitely known to contain a neutron star. The mean observed spectral type of the X-ray-heated mass donor is M5 III. The steady interstellar extinction toward the b...
متن کاملForty Years of X-Ray Binaries
In 2012 it was forty years ago that the discovery of the first X-ray binary Centaurus X-3 became known. That same year it was discovered that apart from the High-Mass X-ray Binaries (HMXBs) there are also Low-Mass X-ray Binaries (LMXBs), and that Cygnus X-1 is most probably a black hole. By 1975 also the new class of Be/X-ray binaries was discovered. After this it took 28 years before ESAs INTE...
متن کاملar X iv : a st ro - p h / 02 11 52 1 v 1 2 4 N ov 2 00 2 Deep Near - Infrared Observations and Identifications of Chandra Sources in the Orion Molecular Cloud
We conducted deep near-infrared (NIR) imaging observations of the Orion molecular cloud 2 and 3 using Quick Infrared Camera on the 88-inch telescope of the University of Hawaii. Our purposes are 1) to generate a comprehensive NIR source catalog of these star forming clouds, and 2) to identify the NIR counterpart of the Chandra X-ray sources that have no counterpart in the Two Micron All Sky Sur...
متن کاملCorrelation between Hard X-ray Peak Flux and Soft X-ray Peak Flux in the Outburst Rise of Low Mass X-ray Binaries
We have analyzed Rossi X-ray timing explorer (RXTE) pointed observations of the outbursts of black hole and neutron star soft X-ray transients in which an initial low/hard state or ‘island’ state, followed by a transition to a softer state, was observed. In three sources, the black hole transient XTE J1550-564, the neutron star transient Aquila X-1 and a quasi-persistent neutron star low mass X...
متن کامل