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Chandra and RXTE spectroscopy of the accreting msec pulsar IGR J00291+5934
Get PDFWe report on an observation of the recently discovered accreting millisecond X-ray pulsar IGR J00291+5934 performed with the RXTE-Proportional Counter Array (PCA) and Chandra-High Energy Transmission Grating Spectrometer (HETGS). The RXTE data are from a twoweek follow-up of the source, while the Chandra observation took place around the end of the follow-up, about 12 days after the discovery of
the source, when the source flux had decreased already by a factor of ten. The analysis of the Chandra data allowed us to extract the most precise X-ray position of IGR J00291+5934, RA = 00h 29m 03.08s, and Dec =+59◦ 34 19.2 (0.6 error), compatible with the optical and radio ones.
We find that the spectra of IGR J00291+5934 can be described by a combination of a thermal component and a power-law. Along the outburst detected by PCA, the power-law photon index showed no particular trend, while the thermal component (∼1 keV, interpreted as a hot spot on
the neutron star surface) became weaker until non-detection. In the simultaneous observation of the weak Chandra /RXTE spectrum, there was no longer any indication of the ∼1 keV thermal component, while we detected a colder thermal component (∼0.4 keV) that we interpret as the
emission from the cold disc. A hint of a 6.4 keV iron line was detected, together with an excess around 6.8 keV and absorption feature around 7.1 keV. The last two features have never been detected in the spectra of accretion-driven millisecond pulsars before and, if confirmed, would
suggest the presence of an expanding hot corona with high outflow velocities
Electromagnetic Characterization of the LISA Verification Binary ZTF J0526+5934
No full text© 2023. The Author(s). Published by the American Astronomical Society. cc-byWe present an analysis of new and archival data to the 20.506 minute LISA verification binary J052610.42+593445.32 (J0526+5934). Our joint spectroscopic and photometric analysis finds that the binary contains an unseen M 1 = 0.89 ± 0.11 M ⊙ CO-core white dwarf primary with an M 2 = 0.38 ± 0.07 M ⊙ post-core-burning subdwarf, or low-mass white dwarf, companion. Given the short orbital period and relatively large total binary mass, we find that LISA will detect this binary with signal-to-noise ratio 44 after 4 yr of observations. J0526+5934 is expected to merge within 1.8 ± 0.3 Myr and likely result in a D6 scenario Type Ia supernova or form a He-rich star that will evolve into a massive single white dwarf
J0526+5934: a peculiar ultra-short-period double white dwarf
Get PDFContext. Ultra-short-period compact binaries are important sources of gravitational waves. The class of short-period compact binaries includes, for example, the progenitors of type Ia supernovae and the progenitors of merger episodes that may lead to massive and magnetic single white dwarfs. J0526+5934 is one such example: it is an unresolved compact binary star with an orbital period of 20.5 min.
Aims. The visible component of J0526+5934 was recently claimed to be a hot sub-dwarf star with a CO white dwarf companion. Our aim is to provide strong observational and theoretical evidence that the primary star is instead an extremely low-mass white dwarf, although the hot sub-dwarf nature cannot be completely ruled out.
Methods. We analysed optical spectra together with time-series photometry of the visible component of J0526+5934 to constrain its orbital and stellar parameters. We also employed evolutionary sequences for low-mass white dwarfs to derive independent values of the primary mass.
Results. From the analysis of our observational data, we find a stellar mass for the primary star in J0526+5934 of 0.26 ± 0.05 M⊙, which perfectly matches the 0.237 ± 0.035 M⊙ independent measurement we derive from the theoretical evolutionary models. This value is considerably lower than the theoretically expected and generally observed mass range for hot sub-dwarf stars, but falls well within the mass limit values of extremely low-mass white dwarfs.
Conclusions. We conclude J0526+5934 is the sixth ultra-short-period detached double white dwarf currently known
Block Card 5934 Lakeside Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: dwelling | 5934 Lakeside Avenue (Toledo, Ohio) | Folk House Style | Maumee Bay | dike | Extension of Warner Place (Toledo, Ohio) | Point Place (Toledo, Ohio) | North Toledo (Toledo, Ohio
Block Card 5934 Katherine Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch houses | 5934 Katherine Avenue (Toledo, Ohio) | Dwelling | Summer Haven Addtion | Greenwood Park Area (Toledo, Ohio
Block Card 5934 Jackman Road
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Dwelling | 5934 Jackman Road (Toledo, Ohio) | Ranch houses | McLains Hopewell Heights (Toledo, Ohio) | Greenwood Area (Toledo, Ohio) | West Toledo Area (Toledo, Ohio
The optical counterpart of IGR J00291+5934 in quiescence
No full textAims.The recent (December 2004) discovery of the sixth accretion-powered
millisecond X-ray pulsar IGR J00291+5934 provides a very good chance to
deepen our knowledge of such systems. Although these systems are well studied at high energies,
poor informations are available for their optical/NIR counterparts during quiescence.
Up to now, only for SAX J1808.4-3658, the first discovered system of this type, we have a
secure multiband detection of its optical counterpart in quiescence. Among the seven known system
IGR J00291+5934 is the one that resembles SAX J1808.4-3658 more closely.
Methods.With the Italian 3.6 m TNG telescope, we have performed deep optical and NIR photometry of the field of IGR J00291+5934 during quiescence in order to look for the presence of a variable counterpart.
Results.We present here the first multiband (VRIJH) detection of the optical and NIR counterpart of
IGR J00291+5934 in quiescence as well as a deep upper limit in the K-band. We obtain an optical
light curve that shows variability consistent with a sinusoidal modulation at the known 2.46 h orbital period and present evidence for a strongly irradiated companion
Phoneme-monitoring in the context of different phonetic sequences
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5934.pdf (Publisher’s version ) (Open Access
Block Card 5934 Holly Glenn Drive
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Dwelling | 5934 Holly Glenn Drive (Toledo, Ohio) | Ranch houses | North Toledo Area (Toledo, Ohio) | Greenwood Area (Toledo, Ohio) | Benalex Heights (Toledo, Ohio
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