Time properties of the the<i>ρ</i>-class burst of the microquasar GRS 1915+105 observed with<i>Beppo</i>SAX in April 1999

Mineo, T.; Massa, F.; Massaro, E.; D’Aí, A.

doi:10.1051/0004-6361/201527609

Cited by 3 publications

(5 citation statements)

References 15 publications

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“…One has to take into account the physical structures of these systems. Both GRS 1915+105 and IGR J17091−3624 have accretion disks around black holes and spectral data indicate that ρ-class bursts are practically unaffected by photon scattering in an energetic corona, as discussed in Mineo et al (2012Mineo et al ( , 2016 for the former source and in Capitanio et al (2012) for the latter one. We verified that when IGR J17091−3624 exhibits ρ bursting series, the luminosity fraction from the corona does not exceed 10% and its optical depth is of the order of ∼0.03 and likely compatible with zero.…”

Section: Discussionmentioning

confidence: 88%

“…Several properties of this repeating bursting state of GRS 1915+105 were investigated in a series of papers Retired. (Massaro et al 2010;Mineo et al 2012Mineo et al , 2016Mineo et al , 2017Massa et al 2013) based on data series obtained in a long-duration study of this source with BeppoSAX in April 1999 and October 2000. According to the definition given in Mineo et al (2012) we distinguish in a burst the following three main segments: an initial increase of the photon count rate, the slow leading trail (SLT), up to the development of a pulse, frequently structured in a few narrow peaks, and terminating with a final decaying trail (FDT) to the initial level.…”

Section: Introductionmentioning

confidence: 99%

“…According to the definition given in Mineo et al (2012) we distinguish in a burst the following three main segments: an initial increase of the photon count rate, the slow leading trail (SLT), up to the development of a pulse, frequently structured in a few narrow peaks, and terminating with a final decaying trail (FDT) to the initial level. In particular, Massa et al (2013) and Mineo et al (2016) discussed the so called hard X delay (HXD): a time lag of the bursts' rising times that increases with the mean photon energy. The HXD had been investigated previously by Janiuk & Czerny (2005) who, applying a crosscorrelation analysis between light curves at different energies, found a delay of the high-energy signal shorter than 1 s, and interpreted it as due to the photon scattering in a hot corona near to the inner disk.…”

Section: Introductionmentioning

confidence: 99%

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Energy scaling of the “heartbeat” pulse width of GRS 1915+105, IGR J17091−3624, and MXB 1730−335 from Rossi-XTE observations

Maselli

Capitanio

Feroci

et al. 2018

A&A

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We investigate some key aspects of the “heartbeat” variability consisting of series of bursts with a slow rise and a fast decay, thus far detected only in GRS 1915+105, IGR J17091−3624, and MXB 1730−335. A previous analysis based on BeppoSAX data of GRS 1915+105 revealed a hard-X delay (HXD), that is a lag of the burst rise at higher energies with respect to lower ones; this leads to narrower pulse widths, w, at higher energies. We here use some light curves of Rossi-XTE observations of GRS 1915+105 for a deeper analysis of this effect and search for its presence in those extracted from some IGR J17091−3624 and MXB 1730−335 observations performed with the same satellite. Our results show that, at variance with GRS 1915+105, no HXD is evident in the light curves of MXB 1730−335 and only a marginal HXD may be argued for IGR J17091−3624. For GRS 1915+105 we find a decreasing trend of the pulse width with energy following a power law w = A ⋅ E−s with an index s ≈ 0.8. Furthermore, we confirm the increase of the HXD with the recurrence time Trec of the bursts in each series that was already found in previous works using BeppoSAX data. Based on a spectral analysis of these three sources we conclude that the differences highlighted in the properties of the “heartbeat” variability are probably related to the different accreting compact object and the eventual presence of a corona in these binary interacting systems.

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Section: Discussionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Energy scaling of the “heartbeat” pulse width of GRS 1915+105, IGR J17091−3624, and MXB 1730−335 from Rossi-XTE observations

Maselli

Capitanio

Feroci

et al. 2018

A&A

Self Cite

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“…The branch with smaller R in typically has smaller C min , F luence, and shorter T rec (see also Figure 3), and vice versa. Mineo et al (2016) investigated two long BeppoSAX pointings, and suggested that the minimum count rate was proportional to the one-third power of the recurrence time (see also Massaro et al 2010). Here, we calculate the Spearman's rank correlation coefficient of ρ/P = 0.70/0 between C min and T rec , confirming their positive correlation.…”

Section: Resultsmentioning

confidence: 99%

A Statistical Analysis of the “Heartbeat” Behavior of GRS 1915+105

Weng

Wang

Cai

et al. 2018

ApJ

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GRS 1915+105 has been active for more than 26 years since it was discovered in 1992. There are hundreds of RXTE pointed observations on this source, and the quasi-regular flares with a slow rise and a sharp decrease (i.e. the "heartbeat" state) were recorded in more than 200 observations. The connections among the disk/corona, jet, and the disk wind at the heartbeat state have been extensively studied. In this work, we firstly perform a statistical analysis of the light curves and the X-ray spectra to investigate this peculiar state. We calculate the parameters for heartbeat cycles, including the recurrence time, the maximum and the minimum count rate, the flare amplitude, and the cumulative radiation for each cycle. The recurrence time has a bimodal distribution ranging from ∼ 20 to ∼ 200 s. The minimum count rate increases with increasing recurrence time; while the maximum count rate remains nearly constant around 2 Crab. Fitting the averaged spectrum for each observation, we find the strong correlations among the recurrence time, the apparent inner radius of the accretion disk (or the color correction factor), and the (nonthermal) X-ray luminosity. We suggest that the true inner edge of the accretion disk might always extend to the marginally stable orbit, while the change in corona size should result in the observed correlations.

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“…A detailed temporal analysis of this observation has been presented in Mineo et al (2016) and therefore we summarize here the main results of the analysis. We evaluated the mean recurrence time of the bursts T rec and the hard X delay (HXD), defined as the delay between the evolution of the count rate and the average energy in each burst, with the methods presented in Massaro et al (2010) and Massa et al (2013) for another dataset collected in 2000 (Obs_2000).…”

Section: Observation: ρ Classmentioning

confidence: 99%

Comparing theρandχclass spectra of the microquasar GRS 1915+105 observed withBeppoSAX

Mineo

Massaro

Massa

et al. 2017

A&A

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Context. BeppoSAX observed GRS 1915+105 during two variability classes at the same 2-10 keV flux level. The ρ class is characterized by quasi-periodic flares recurring on a timescale of 1 to 2 min, namely heartbeat, while the χ class is characterized by no strong temporal variability. Aims. The aim of this work is to coherently analyze the source spectrum in these two classes and to gain insight into the source conditions that inset the heartbeats. Methods. A single χ spectrum was accumulated, while ρ data were split in runs where five phase-resolved spectra were selected. In addition to the multicolor disc black body, the fitting model includes a hybrid Comptonization plus a Compton reflection component. Results. Our results show that the emission in the ρ class is dominated by the multi-temperature disk, while in the χ class the Comptonised component is dominant. The disk temperature varies between a maximum of 1.95 ± 0.11 keV reached at the peak and a minimum of 0.95 +0.08 −0.20 keV in the χ class. In both classes we detect a significant contribution from a non-thermal electron population to the total Comptonized emission. A broadened iron emission line is detected in the χ spectrum. We interpret the line shape as being due to reflection from an accretion disk extremely close to the black-hole (R in = 4.1 +1.5 −0.9 gravitational radii), with an equivalent width of 200 ± 20 eV. Concomitantly, upper limits of ∼150 eV can be derived from the ρ spectra. Conclusions. In the framework of coupled disc-corona models, these results point out that the source emission is strongly affected by the fractions of accretion energy distributed between the disk, the corona, and possibly the wind, with no indication on the conditions that inset the heartbeats.

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Time properties of the theρ-class burst of the microquasar GRS 1915+105 observed withBeppoSAX in April 1999

Cited by 3 publications

References 15 publications

Energy scaling of the “heartbeat” pulse width of GRS 1915+105, IGR J17091−3624, and MXB 1730−335 from Rossi-XTE observations

Energy scaling of the “heartbeat” pulse width of GRS 1915+105, IGR J17091−3624, and MXB 1730−335 from Rossi-XTE observations

A Statistical Analysis of the “Heartbeat” Behavior of GRS 1915+105

Comparing theρandχclass spectra of the microquasar GRS 1915+105 observed withBeppoSAX

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