THE OPTICAL COMPANION TO THE INTERMEDIATE-MASS MILLISECOND PULSAR J1439-5501 IN THE GALACTIC FIELD

Journal Article · Tue Aug 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/773/2/127· OSTI ID:22130980

Pallanca, C.; Lanzoni, B.; Dalessandro, E.; Ferraro, F. R. ^[1]; Possenti, A.; Burgay, M. ^[2]; Salaris, M. ^[3]

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1. Dipartimento di Fisica e Astronomia, Universita degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy)
2. INAF-Osservatorio Astronomico di Cagliari, localita Poggio dei Pini, strada 54, I-09012 Capoterra (Italy)
3. Astrophysics Research Institute, Liverpool John Moores University (United Kingdom)

We present the identification of the companion star to the intermediate-mass binary pulsar (PSR) J1439-5501 obtained by means of ground-based deep images in the B, V, and I bands, acquired with FORS2 mounted at the European Southern Observatory (ESO)-Very Large Telescope (VLT). The companion is a massive white dwarf (WD) with B = 23.57 {+-} 0.02, V = 23.21 {+-} 0.01, and I = 22.96 {+-} 0.01, located at only {approx}0.''05 from the pulsar radio position. Comparing the WD location in the (B, B-V) and (V, V-I) color-magnitude diagrams with theoretical cooling sequences, we derived a range of plausible combinations of companion masses (1 M{sub Sun} {approx}< M{sub COM} {approx}< 1.3 M{sub Sun }), distances (d {approx}< 1200 pc), radii ({approx}< 7.810{sup -3} R{sub Sun }), and temperatures (T=31350{sup +21500}{sub -7400}). From the PSR mass function and the estimated mass range we also constrained the inclination angle i {approx}> 55 Degree-Sign and the pulsar mass (M{sub PSR} {approx}< 2.2 M{sub Sun }). The comparison between the WD cooling age and the spin-down age suggests that the latter is overestimated by a factor of about 10.

• OSTI ID: 22130980
• Journal Information: Astrophysical Journal, Vol. 773, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COLOR
COOLING
GALAXIES
IMAGES
INCLINATION
MASS
PULSARS
TELESCOPES
WHITE DWARF STARS