The magnetar candidate AX  J1818.8−1559

Mereghetti, S.; Esposito, P.; Tiengo, A.; Götz, D.; Israel, G. L.; Luca, A. De

doi:10.1051/0004-6361/201219907

Cited by 12 publications

(13 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…b Preceding Suzaku studies: SGR 1806−20 (Esposito et al 2007;Nakagawa et al 2009), 1E 1841−45 (Morii et al 2010), SGR 1900+14 (Nakagawa et al 2009) 4U 0142+61 Makishima et al 2014), AX J1818.8−586 (Mereghetti et al 2012), 1E 1547.0−5408 (Enoto et al 2010b;Iwahashi et al 2013;Enoto et al 2012;Makishima et al 2015), SGR 0501+4516 (Enoto et al 2009(Enoto et al , 2010cNakagawa et al 2011) CXOU J164710.2−455216 (Naik et al 2008), SGR 1833−0832 ), Swift J1822.3−1606, and Paper I. c Objects are sorted by the dipole field B d calculated from the period P and its derivativeṖ assuming the magnetic dipole radiation. d Type of observations: PV (Performance Verification phase, i.e., first 9 month after the launch), AO (Announcement of Opportunity observations), ToO (Target of Opportunity observations), and Key (Key Project observations).…”

Section: Reduction Of Broad-band Suzaku Spectramentioning

confidence: 99%

“…Mereghetti et al (2012) performed a Suzaku follow-up observation, combined with Chandra and XMM-Newton spectral studies, after a detection of a magnetar-like short burst with INTEGRAL in 2007. Due to low photon counts of the XIS spectra, we fixed N H value within the error range of (Mereghetti et al 2012), and the derived flux and kT values are consistent with their report. …”

Section: Ax J18188−1559mentioning

confidence: 99%

See 1 more Smart Citation

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

Enoto¹,

Shibata²,

Kitaguchi³

et al. 2017

ApJS

116

View full text Add to dashboard Cite

Studies were made of the 1-70 keV persistent spectra of fifteen magnetars as a complete sample observed with Suzaku from 2006 to 2013. Combined with early NuSTAR observations of four hard X-ray emitters, nine objects showed a hard power-law emission dominating at 10 keV with the 15-60 keV flux of ∼1-11 × 10 −11 ergs s −1 cm −2 . The hard X-ray luminosity L h , relative to that of a soft-thermal surface radiation L s , tends to become higher toward younger and strongly magnetized objects. Updated from the previous study, their hardness ratio, defined as ξ = L h /L s , is correlated with the measured spin-down rateṖ as ξ = 0.62 × (Ṗ /10 −11 s s −1 ) 0.72 , corresponding with positive and negative correlations of the dipole field strength B d (ξ ∝ B d) and the characteristic age τ c (ξ ∝ τ −0.68 c ), respectively. Among our sample, five transients were observed during X-ray outbursts, and the results are compared with their long-term 1-10 keV flux decays monitored with Swift/XRT and RXTE/PCA. Fading curves of three bright outbursts are approximated by an empirical formula used in the seismology, showing a ∼10-40 d plateau phase. Transients show the maximum luminosities of L s ∼1035 erg s −1 , which is comparable to those of the persistently bright ones, and fade back to 10 32 erg s −1 . Spectral properties are discussed in a framework of the magnetar hypothesis.

show abstract

Section: Reduction Of Broad-band Suzaku Spectramentioning

confidence: 99%

Section: Ax J18188−1559mentioning

confidence: 99%

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

Enoto¹,

Shibata²,

Kitaguchi³

et al. 2017

ApJS

116

View full text Add to dashboard Cite

show abstract

“…Other examples of transients followed up at the SRT are SGR J1935+2154 (Israel et al 2014), SGR J0755-2933 (Barthelmy et al 2016) and the magnetar candidate SGR J1819-1600 (Mereghetti et al 2012;Page et al 2015).…”

Section: Target Of Opportunity Observationsmentioning

confidence: 99%

The Sardinia Radio Telescope

Prandoni

Murgia

Tarchi

et al. 2017

A&A

View full text Add to dashboard Cite

Context. The Sardinia Radio Telescope (SRT) is the new 64 m dish operated by the Italian National Institute for Astrophysics (INAF).Its active surface, comprised of 1008 separate aluminium panels supported by electromechanical actuators, will allow us to observe at frequencies of up to 116 GHz. At the moment, three receivers, one per focal position, have been installed and tested: a 7-beam K-band receiver, a mono-feed C-band receiver, and a coaxial dual-feed L/P band receiver. The SRT was officially opened in September 2013, upon completion of its technical commissioning phase. In this paper, we provide an overview of the main science drivers for the SRT, describe the main outcomes from the scientific commissioning of the telescope, and discuss a set of observations demonstrating the scientific capabilities of the SRT. Aims. The scientific commissioning phase, carried out in the 2012-2015 period, proceeded in stages following the implementation and/or fine-tuning of advanced subsystems such as the active surface, the derotator, new releases of the acquisition software, etc. One of the main objectives of scientific commissioning was the identification of deficiencies in the instrumentation and/or in the telescope subsystems for further optimization. As a result, the overall telescope performance has been significantly improved. Methods. As part of the scientific commissioning activities, different observing modes were tested and validated, and the first astronomical observations were carried out to demonstrate the science capabilities of the SRT. In addition, we developed astronomeroriented software tools to support future observers on site. In the following, we refer to the overall scientific commissioning and software development activities as astronomical validation. Results. The astronomical validation activities were prioritized based on technical readiness and scientific impact. The highest priority was to make the SRT available for joint observations as part of European networks. As a result, the SRT started to participate (in shared-risk mode) in European VLBI Network (EVN) and Large European Array for Pulsars (LEAP) observing sessions in early 2014. The validation of single-dish operations for the suite of SRT first light receivers and backends continued in the following year, and was concluded with the first call for shared-risk early-science observations issued at the end of 2015. As discussed in the paper, the SRT capabilities were tested (and optimized when possible) for several different observing modes: imaging, spectroscopy, pulsar timing, and transients.

show abstract

“…A posteriori visualisation of known sources identified separation between GRBs and SGRs. GRB 071017 is very likely a magnetar misclassified as a short gamma-ray burst [14]. This division could help in determining further observational strategy of an unknown flare and to put constraint on a fraction of magnetars among short GRBs.…”

Section: Discussionmentioning

confidence: 98%

Search and Machine Learning Classification of Short Untriggered Transients

Topinka¹,

Hudec²

2015

Proceedings of Swift: 10 Years of Discovery — PoS(SWIFT 10)

View full text Add to dashboard Cite

An intense search through the INTEGRAL IBIS/ISGRI data archive revealed a large number of untriggered flares on a millisecond time scale. As the IBIS detector uses a coded mask, localisation of those flares is hard due to low number statistics in the deconvolution process. The identified flares are used as an input for further data processing. A machine learning clustering algorithm reveals several groups of objects. This fast classification method can separate e.g. short gamma-ray bursts from soft gamma-ray repeater flares. Discriminating between different classes of objects allows to adjust strategies for real-time follow-up observations and to constrain fraction of SGRs among short GRBs.

show abstract

The magnetar candidate AX J1818.8−1559

Cited by 12 publications

References 45 publications

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

The Sardinia Radio Telescope

Search and Machine Learning Classification of Short Untriggered Transients

Contact Info

Product

Resources

About