Multiband Optical Follow-up Observations of GRB 020813 at the Kiso and Bisei Observatories

Urata, Y.; Nishiura, S.; Miyata, Takashi; Mito, Hiroyuki; Kawabata, Tetsuya; Nakada, Y.; Aoki, Tsutomu; Soyano, Takao; Tarusawa, K.; Yoshida, A.; Tamagawa, Toru; Makishima, Kazuo

doi:10.1086/378789

Cited by 22 publications

(26 citation statements)

References 15 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the published positions of the V-band break time (t break,V ) are not in close agreement. Thus, Urata et al (2003) report t break,V = 0.22 ± 0.01 days, whereas Covino et al (2003a) give t break,V = 0.50 ± 0.27 days. In addition, Li et al (2003) determined an R-band break time at t break,R = 0.14 ± 0.03 based on data of the KAIT telescope.…”

Section: Determination Of the Break Timementioning

confidence: 96%

“…After the optical afterglow (OA) discovery (Fox et al 2002) it was subject of an intensive radio (Frail & Berger 2002;Bremer & Castro-Tirado 2002), X-ray (Butler et al 2003), optical (Li et al 2003;Laursen & Stanek 2003;Urata et al 2003), near-IR (Covino et al 2003a), polarimetric (Barth et al 2002; and spectroscopic Barth et al 2003) follow-up.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

GRB 020813: Polarization in the case of a smooth optical decay

Gorosabel¹,

Rol²,

Covino³

et al. 2004

A&A

View full text Add to dashboard Cite

Abstract. We present the results of a VLT polarimetric monitoring campaign of the GRB 020813 optical afterglow carried out in three nights, from 0.88 to 4.20 days after the gamma-ray event. The mean values of the degree of linear polarization (P) and its position angle (θ) resulting from our campaign are P = 1.18 ± 0.10% and θ = 148.7• ± 2.3 • , after correcting for Galactic interstellar polarization. Our VLT data set is most naturally described by a constant degree of linear polarization and position angle, nonetheless a slow θ evolution cannot be entirely ruled out by our data. The VLT monitoring campaign did not reveal either a significant θ rotation respect to the Keck spectropolarimetric observations performed ∼0.25 days after the GRB . However, P is a factor of two lower than the polarization degree measured from Keck. Additionally, the VLT polarization data allowed us to construct an accurate V-band light curve. The V-band photometric data revealed a smooth light curve with a break located between the last Keck and our first VLT polarimetric measurement, 0.33 < t break,V < 0.88 days after the GRB. The typical magnitude fluctuations of the VLT V-band lightcurve are 0.003 mag, 0.010 mag and 0.016 mag for our three observing nights, respectively. We speculate that the stability of θ might be related to the smoothness of the light curve.

show abstract

Section: Determination Of the Break Timementioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

GRB 020813: Polarization in the case of a smooth optical decay

Gorosabel¹,

Rol²,

Covino³

et al. 2004

A&A

View full text Add to dashboard Cite

show abstract

“…If these results are true, then it is obvious that the existence of the early break is consistent with what we have predicted above that an achromatic bump would appear at the time T c T6:4 hr. For the result of T em % 0:2 days from Urata et al (2003), we concluded that the continuous injection from GRB 020813 would be due to a pulsar with B p;15 % 0:68 and P 0 % 1:98 ms; T c % 0:3 hr could also be obtained. However, more complete analysis of the V-band data by Gorosabel, Rol, & Covino (2003, including the data of Urata et al 2003) indicated that there is no evidence for the existence of an early bump break.…”

Section: Discussionmentioning

confidence: 83%

“…For the result of T em % 0:2 days from Urata et al (2003), we concluded that the continuous injection from GRB 020813 would be due to a pulsar with B p;15 % 0:68 and P 0 % 1:98 ms; T c % 0:3 hr could also be obtained. However, more complete analysis of the V-band data by Gorosabel, Rol, & Covino (2003, including the data of Urata et al 2003) indicated that there is no evidence for the existence of an early bump break. They obtained a jet break at the time 0:33 days < t break;V < 0:88 days, in agreement with the results by Covino et al (2003;t break;V ¼ 0:50 days).…”

Section: Discussionmentioning

confidence: 83%

See 1 more Smart Citation

Can the Bump Be Observed in the Early Afterglow of Gamma‐Ray Bursts with X‐Ray Line Emission Features?

Gao¹,

Wei

2004

ApJ

View full text Add to dashboard Cite

Extremely powerful emission lines are observed in the X-ray afterglow of several gamma-ray bursts (GRBs). The energy contained in the illuminatingcontinuum that is responsible for the line production exceeds 10 51 ergs, much higher than that of the collimated GRBs, constraining the models that might explain the production of X-ray emission lines. In this paper, we argue that this energy can come from a continuous postburst outflow. Focusing on a central engine of highly magnetized millisecond pulsar or magnetar, we find that the afterglow can be affected by the illuminating continuum, and therefore a distinct achromatic bump can be observed in the early afterglow light curves. With the luminosity of the continuous outflow that produces the line emission, we define the upper limit of the time when the bump feature appears. We argue that the reason why the achromatic bumps have not been detected so far is that the bumps appear at too early a time to be observed.

show abstract

Clustering of the optical-afterglow luminosities of long gamma-ray bursts

Nardini

Ghisellini

Ghirlanda

et al. 2006

A&A

112

View full text Add to dashboard Cite

We studied the optical afterglows of the 24 pre-SWIFT gamma-ray bursts (GRBs) with both known spectroscopic redshift and published estimates of the optical extinction in the source frame. We found an unexpected clustering of the optical-afterglow luminosities measured 12 h (source frame time) after the trigger. For 21 out of 24 bursts, the distribution of the optical luminosities is narrower than the distribution of the X-ray luminosities, and even narrower than the distribution of the ratio between the monochromatic optical luminosities and the total isotropic, emitted prompt energy. Three bursts stand out from the distribution of the other sources, being underluminous by a factor ∼15. We compare this result with another somewhat analogous result concerning the luminosity of the X-ray afterglows studied earlier. We constructed the optical to X-ray spectral energy distribution for all our GRBs. For all but a minority of them, the optical and the X-ray emissions are consistent with being produced by the same radiation process. We discuss our results in the framework of the "standard" external-shock synchrotron model. Finally, we consider the behavior of the first GRBs of known redshifts detected by SWIFT. We find that these SWIFT GRBs entirely confirm our findings.

show abstract

Multiband Optical Follow-up Observations of GRB 020813 at the Kiso and Bisei Observatories

Cited by 22 publications

References 15 publications

GRB 020813: Polarization in the case of a smooth optical decay

GRB 020813: Polarization in the case of a smooth optical decay

Can the Bump Be Observed in the Early Afterglow of Gamma‐Ray Bursts with X‐Ray Line Emission Features?

Clustering of the optical-afterglow luminosities of long gamma-ray bursts

Contact Info

Product

Resources

About