GRB 161017A, the circumburst environment is an intermediate regime between the homogeneous interstellar medium and wind-type medium

2020 ◽  
Vol 29 (06) ◽  
pp. 2050043 ◽  
Author(s):  
Qi-Qi Zhou ◽  
Shuang-Xi Yi ◽  
Xiao-Li Huang ◽  
Shu-Qing Zhong ◽  
Yuan-Chuan Zou ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Light Curve ◽  
Density Profile ◽  
Early Time ◽  
Intermediate Regime ◽  
X Ray ◽  
Central Engine ◽  
Forward Shock ◽  
Optical Light Curve ◽  
Long Acting

We investigate the multi-band properties of the GRB 161017A with [Formula: see text], which was detected by Swift and Fermi satellites, and other instruments. The optical and X-ray afterglows were all detected at early times after the prompt emission. The optical light curve shows a very bright onset peak at about 100 s for 13 mag of [Formula: see text]-band, while the X-ray light curve occurs several flares at the beginning. We investigate the origin of X-ray and optical afterglows by analyzing the optical and X-ray data. Considering the smooth onset bump in the early time of the optical band and the erratic pulses for the X-ray lightcurve, we suppose that the early optical afterglow may be produced by the external shock, while the early time of X-ray light curve is dominated by flares. Therefore, GRB optical afterglows with smooth onset bump features at early time are possibly produced by external — forward shock (FS). According to the fireball external-model, the temporal slopes of the onset bumps are determined by both the medium density profile and the electron spectral index. Therefore, the afterglow onset bumps would be an ideal probe to study the properties of the fireball and the circumburst medium. The density profile has a slope of [Formula: see text], which suggests that the circumburst environment of the GRB 161017A would be an intermediate regime that are between the homogeneous interstellar medium (ISM) and wind-type medium. In addition, the optical light curve of the GRB 161017A exhibits a plateau feature and rebrightening after the onset bump, which may be related to the long-acting central engine of GRBs.

The Optical Light Curve of LMC X-4 and the 30-Day X-Ray Period

1981 ◽  
pp. 405-406
Author(s):  
C. Chevalier ◽  
S. A. Ilovaisky ◽  
C. Motch ◽  
M. Pakull ◽  
J. Lub ◽  
...  
Keyword(s):  
Light Curve ◽  
X Ray ◽  
Optical Light Curve

The optical light curve of LMC X-4 and the 30-day X-ray period

1981 ◽  
Vol 30 (1-4) ◽  
pp. 405-406 ◽  
Author(s):  
C. Chevalier ◽  
S. A. Ilovaisky ◽  
C. Motch ◽  
M. Pakull ◽  
J. Lub ◽  
...  
Keyword(s):  
Light Curve ◽  
X Ray ◽  
Optical Light Curve

THE INTERPLAY OF PROMPT AND AFTERGLOW EMISSION IN GRB 060418

2008 ◽  
Vol 17 (09) ◽  
pp. 1343-1349 ◽  
Author(s):  
S. D. VERGANI ◽  
D. MALESANI ◽  
E. MOLINARI
Keyword(s):  
Gamma Rays ◽  
Spectral Properties ◽  
Gamma Ray ◽  
Early Time ◽  
Lorentz Factor ◽  
X Ray ◽  
Central Engine ◽  
Low Energies ◽  
Prompt Emission

We present observations of the early afterglow emission of GRB 060418. Thanks to the simultaneous coverage at optical, X-ray and gamma-ray wavelengths, we can detect and separate the external shock emission (visible in the optical and late X-ray data) and the central engine activity (early X and gamma rays). The two components are clearly distinguished based on temporal and spectral properties. The detection of the afterglow onset (in the optical) allows the determination of the fundamental fireball properties, namely its bulk Lorentz factor and total energy. The early time X-ray flare closely resembles the prompt emission gamma-ray pulses in its temporal profile, being wider at low energies and showing lags between the hard and soft bands. This provides a strong suggestion that X-ray flares are a continuation of the prompt emission.

An Extremely Massive White Dwarf of the Symbiotic Classical Nova V407 Cyg as Suggested by the RS Oph and U SCO Models

2012 ◽  
Vol 21 (1-2) ◽  
Author(s):  
I. Hachisu ◽  
M. Kato
Keyword(s):  
Light Curve ◽  
White Dwarf ◽  
Early Phase ◽  
Symbiotic Star ◽  
X Ray ◽  
Classical Nova ◽  
Optical Light Curve ◽  
Nova Outburst

AbstractWe have analyzed the optical light curve of the symbiotic star V407 Cyg that underwent a classical nova outburst in 2010 March. Being guided by a supersoft X-ray phase observed during days 20-40 after the nova outburst, we are able to reproduce the light curve during a very early phase of the nova outburst. Our model consists of an outbursting white dwarf and an extended equatorial disk. An extremely massive white dwarf of 1.35-1.37 M

scholarly journals Optical, X-ray, and γ-ray observations of the candidate transitional millisecond pulsar 4FGL J0427.8-6704

2020 ◽  
Vol 494 (3) ◽  
pp. 3912-3926
Author(s):  
M R Kennedy ◽  
R P Breton ◽  
C J Clark ◽  
V S Dhillon ◽  
M Kerr ◽  
...  
Keyword(s):  
Light Curve ◽  
Time Scales ◽  
Periodic Oscillation ◽  
Optical Data ◽  
Data Sets ◽  
Millisecond Pulsar ◽  
X Ray ◽  
State Classification ◽  
Optical Light Curve ◽  
Γ Ray

ABSTRACT We present an optical, X-ray, and γ-ray study of 1SXPS J042749.2-670434, an eclipsing X-ray binary that has an associated γ-ray counterpart, 4FGL J0427.8-6704. This association has led to the source being classified as a transitional millisecond pulsar (tMSP) in an accreting state. We analyse 10.5 yr of Fermi LAT data and detect a γ-ray eclipse at the same phase as optical and X-ray eclipses at the >5 σ level, a significant improvement on the 2.8 σ level of the previous detection. The confirmation of this eclipse solidifies the association between the X-ray source and the γ-ray source, strengthening the tMSP classification. However, analysis of several optical data sets and an X-ray observation do not reveal a change in the source’s median brightness over long time-scales or a bi-modality on short time-scales. Instead, the light curve is dominated by flickering, which has a correlation time of 2.6 min alongside a potential quasi-periodic oscillation at ∼21 min. The mass of the primary and secondary stars is constrained to be $M_1=1.43^{+0.33}_{-0.19}$ M⊙ and $M_2=0.3^{+0.17}_{-0.12}$ M⊙ through modelling of the optical light curve. While this is still consistent with a white dwarf primary, we favour the tMSP in a low accretion state classification due to the significance of the γ-ray eclipse detection.

scholarly journals SN 2020bvc: A Broad-line Type Ic Supernova with a Double-peaked Optical Light Curve and a Luminous X-Ray and Radio Counterpart

2020 ◽  
Vol 902 (1) ◽  
pp. 86 ◽  
Author(s):  
Anna Y. Q. Ho ◽  
S. R. Kulkarni ◽  
Daniel A. Perley ◽  
S. Bradley Cenko ◽  
Alessandra Corsi ◽  
...  
Keyword(s):  
Light Curve ◽  
Broad Line ◽  
X Ray ◽  
Optical Light Curve ◽  
Line Type

scholarly journals Light Curve Models for SN 1987A and Diagnosis of Supernova Interior

1988 ◽  
Vol 108 ◽  
pp. 319-334
Author(s):  
Ken’ichi Nomoto ◽  
Toshikazu Shigeyama ◽  
Masa-aki Hashimoto
Keyword(s):  
Light Curve ◽  
Reasonable Agreement ◽  
Light Curves ◽  
Shock Propagation ◽  
Helium Abundance ◽  
X Ray ◽  
Sn 1987A ◽  
Shock Heating ◽  
Helium Stars ◽  
Optical Light Curve

AbstractPresupernova evolution of the progenitor of SN 1987A, hydrodynamics of explosion (shock propagation, explosive nucleosynthesis), optical light curve due to shock heating and 56Co decay, and X-ray and γ-ray light curves are calculated and compared with the observations of SN 1987A. Constraints on the mass of the hydrogen-rich envelope Menv (i.e., mass loss history) and the helium abundance in the envelope are obtained from the progenitor’s blue-red-blue evolution as well as from the light curve. The explosion energy E and the mass and distribution of 56Ni are inferred from the light curves. Models and observations are in reasonable agreement for E/Menv = 1.5 ± 0.5 × 1050 erg/M⊙, Menv = 5 - 10 M⊙, and MNi ∼ 0.07 M⊙. Mixing of 56Ni into the envelope is indicated.Light curves of exploding bare helium stars are also calculated to see whether the observed Type Ib supernova light curves can be accounted for.

scholarly journals Late-time observations of the extraordinary Type II supernova iPTF14hls

2019 ◽  
Vol 621 ◽  
pp. A30 ◽  
Author(s):  
J. Sollerman ◽  
F. Taddia ◽  
I. Arcavi ◽  
C. Fremling ◽  
C. Fransson ◽  
...  
Keyword(s):  
Light Curve ◽  
Late Time ◽  
Type Ii ◽  
Optical Photometry ◽  
Central Engine ◽  
Processed Material ◽  
Optical Light Curve ◽  
Steep Decline ◽  
The Many ◽  
Additional Space

Aims. We study iPTF14hls, a luminous and extraordinary long-lived Type II supernova, which lately has attracted much attention and disparate interpretation. Methods. We have presented new optical photometry that extends the light curves up to more than three years past discovery. We also obtained optical spectroscopy over this period, and furthermore present additional space-based observations using Swift and HST. Results. After an almost constant luminosity for hundreds of days, the later light curve of iPTF14hls finally fades and then displays a dramatic drop after about 1000 d, but the supernova is still visible at the latest epochs presented. The spectra have finally turned nebular, and our very last optical spectrum likely displays signatures from the deep and dense interior of the explosion. A high-resolution HST image highlights the complex environment of the explosion in this low-luminosity galaxy. Conclusions. We provide a large number of additional late-time observations of iPTF14hls, which are (and will continue to be) used to assess the many different interpretations for this intriguing object. In particular, the very late (+1000 d) steep decline of the optical light curve is difficult to reconcile with the proposed central engine models. The lack of very strong X-ray emission, and the emergence of intermediate-width emission lines including [S II] that we propose originate from dense, processed material in the core of the supernova ejecta, are also key observational tests for both existing and future models.

scholarly journals The luminous host galaxy, faint supernova and rapid afterglow rebrightening of GRB 100418A

2018 ◽  
Vol 620 ◽  
pp. A190 ◽  
Author(s):  
A. de Ugarte Postigo ◽  
C. C. Thöne ◽  
K. Bensch ◽  
A. J. van der Horst ◽  
D. A. Kann ◽  
...  
Keyword(s):  
Light Curve ◽  
Gamma Ray ◽  
Formation Rate ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Absorption And Emission ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Central Engine

Context. Long gamma-ray bursts (GRBs) give us the chance to study both their extreme physics and the star-forming galaxies in which they form. Aims. GRB 100418A, at a redshift of z = 0.6239, had a bright optical and radio afterglow, and a luminous star-forming host galaxy. This allowed us to study the radiation of the explosion as well as the interstellar medium of the host both in absorption and emission. Methods. We collected photometric data from radio to X-ray wavelengths to study the evolution of the afterglow and the contribution of a possible supernova (SN) and three X-shooter spectra obtained during the first 60 h. Results. The light curve shows a very fast optical rebrightening, with an amplitude of ∼3 magnitudes, starting 2.4 h after the GRB onset. This cannot be explained by a standard external shock model and requires other contributions, such as late central-engine activity. Two weeks after the burst we detect an excess in the light curve consistent with a SN with peak absolute magnitude MV = −18.5 mag, among the faintest GRB-SNe detected to date. The host galaxy shows two components in emission, with velocities differing by 130 km s−1, but otherwise having similar properties. While some absorption and emission components coincide, the absorbing gas spans much higher velocities, indicating the presence of gas beyond the star-forming regions. The host has a star formation rate of SFR = 12.2 M⊙ yr−1, a metallicity of 12 + log(O/H) = 8.55, and a mass of 1.6 × 109 M⊙. Conclusions. GRB 100418A is a member of a class of afterglow light curves which show a steep rebrightening in the optical during the first day, which cannot be explained by traditional models. Its very faint associated SN shows that GRB-SNe can have a larger dispersion in luminosities than previously seen. Furthermore, we have obtained a complete view of the host of GRB 100418A owing to its spectrum, which contains a remarkable number of both emission and absorption lines.

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