SearcharxivSearch

arXiv · 2310.17287

Ready for O4 II: GRANDMA Observations of Swift GRBs during eight-weeks of Spring 2022

Abstract

We present a campaign designed to train the GRANDMA network and its infrastructure to follow up on transient alerts and detect their early afterglows. In preparation for O4 II campaign, we focused on GRB alerts as they are expected to be an electromagnetic counterpart of gravitational-wave events. Our goal was to improve our response to the alerts and start prompt observations as soon as possible to better prepare the GRANDMA network for the fourth observational run of LIGO-Virgo-Kagra (which started at the end of May 2023), and future missions such as SM. To receive, manage and send out observational plans to our partner telescopes we set up dedicated infrastructure and a rota of follow-up adcates were organized to guarantee round-the-clock assistance to our telescope teams. To ensure a great number of observations, we focused on Swift GRBs whose localization errors were generally smaller than the GRANDMA telescopes' field of view. This allowed us to bypass the transient identification process and focus on the reaction time and efficiency of the network. During 'Ready for O4 II', 11 Swift/INTEGRAL GRB triggers were selected, nine fields had been observed, and three afterglows were detected (GRB 220403B, GRB 220427A, GRB 220514A), with 17 GRANDMA telescopes and 17 amateur astronomers from the citizen science project Kilonova-Catcher. Here we highlight the GRB 220427A analysis where our long-term follow-up of the host galaxy allowed us to obtain a photometric redshift of $z=0.82\pm0.09$, its lightcurve elution, fit the decay slope of the afterglows, and study the properties of the host galaxy.

Explore related subjects

Keep this discovery

BibTeXRIS

I. Tosta e Melo, J. -G. Ducoin, Z. Vidadi, C. Andrade, V. Rupchandani, S. Agayeva, J. Abdelhadi, L. Abe, O. Aguerre-Chariol, V. Aivazyan, S. Alishov, S. Antier, J. -M. Bai, A. Baransky, S. Bednarz, Ph. Bendjoya, Z. Benkhaldoun, S. Beradze, M. A. Bizouard, U. Bhardwaj, M. Blazek, M. Boër, E. Broens, O. Burkhonov, N. Christensen, J. Cooke, W. Corradi, M. W. Coughlin, T. Culino, F. Daigne, D. Dornic, P. -A. Duverne, S. Ehgamberdiev, L. Eymar, A. Fouad, M. Freeberg, B. Gendre, F. Guo, P. Gokuldass, N. Guessoum, E. Gurbanov, R. Hainich, E. Hasanov, P. Hello, R. Inasaridze, A. Iskandar, N. Ismailov, A. Janati, T. Jegou du Laz, D. A. Kann, S. Karpov, R. W. Kiendrebeogo, A. Klotz, R. Kneip, N. Kochiashvili, A. Kaeouach, K. Kruiswijk, M. Lamoureux, N. Leroy, W. L. Lin, J. Mao, D. Marchais, M. Mašek, T. Midavaine, A. Moller, D. Morris, R. Natsvlishvili, F. Navarete, A Nicuesa Guelbenzu, K. Noonan, K. Noysena, A. Oksanen, N. B. Orange, C. Pellouin, J. Peloton, H. W. Peng, M. Pilloix, A. Popowicz, T. Pradier, O. Pyshna, G. Raaijmakers, Y. Rajabov, A. Rau, C. Rinner, J. -P. Rivet, A. S. Ryh, M. Sabil, T. Sadibekova, N. Sasaki, M. Serrau, A. Simon, A. Shokry, K. Smith, O. Sokoliuk, X. Song, A. Takey, P. Thierry, Y. Tillayev, D. Turpin, A. de Ugarte Postigo. 2023-10-26. Ready for O4 II: GRANDMA Observations of Swift GRBs during eight-weeks of Spring 2022. https://arxiv.org/abs/2310.17287

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

IceCube neutrino point-source searches in the direction of the KM3NeT ultra-high-energy event

While still under construction, the KM3NeT Astroparticle Research with Cosmics in the Abyss (ARCA) detector recorded a $\sim$200 PeV neutrino on February 13th, 2023. This event is the highest-energy neutrino reported. IceCube, a cubic kilometer neutrino detector located at the geographic South Pole, has previously detected neutrinos up to approximately 10 PeV. We search for high-energy neutrinos from the location of the KM3NeT event using 15 years of IceCube data and considering three temporal hypotheses: steady or flaring in time coincidence, or at an arbitrary time. We find no evidence for neutrino emission for any of the studies performed. Correspondingly, we set upper limits on the neutrino flux from a point source in the direction of KM3-230213A. We compare these limits to KM3NeT's estimated flux and show that an astrophysical explanation of this event is strongly constrained for a variety of spectral assumptions for a steady or transient point source with the flux inferred from the single KM3NeT ultra-high-energy event assuming a spectral index of 2.0.

astro-ph.HE

Evidence for the binary nature of the long-period radio transient ASKAP/DART J1832-0911

Long-period transients are a class of periodic pulsed radio source repeating on the minute to hour timescale. Recently, an increasing number of them are being identified as binary systems, specifically white dwarfs with low-mass main-sequence companions. In this work we analyse the most luminous long-period transient discovered to date, ASKAP/DART J1832-0911, with two years of radio data, and propose that it, too, may be a white dwarf system, although in a far more compact orbit than the aforementioned. The pulses are composed of quasi-periodic components which evolve in a systematic way over days and months. The source is highly linearly or elliptically polarised and its brightness enabled very high signal-to-noise measurement of the time-resolved Faraday rotation measure, which was found to vary across pulse phase. The linear polarisation position angle, circular polarised fraction, and spectral index also varied systematically in ways not typical of pulsars and magnetars. We show that an ultra-compact asynchronous polar explains much of the phenomenology of ASKAP/DART J1832-0911, in particular the evolution of the pulse morphology, rotation measure variation, and periodic X-ray emission, although we cannot conclusively prove a binary nature. However, our model makes testable predictions.

astro-ph.HE

Nonbirefringent model of orthogonal polarization modes in radio pulsars - New view on S swing and mode structure in pulsar beam

Two orthogonal polarization modes observed in radio pulsar signals have long been attributed to proper modes of wave oscillation in strongly magnetized plasma. Yet it has been shown recently that they show up readily for extended emission regions that produce incoherently-superposed polarization signal. In this paper we present a two-dimensional polarization model based on incoherent superposition of radio signals. The model involves a single proper mode, say the O mode, but leads to the appearance of two orthogonal polarization tracks and naturally produces the triple form of polarization mode segregation in averaged profiles (central mode flanked on boths sides by another mode), as well as the displacement of modes in latitude, previously inferred from beam mapping. In the case of conal emission regions, the modelled polarization tends to mimic general polarization properties of the rotating vector model (RVM). However, the reason for this is the symmetry of the emission region - not the usual projection of dipolar magnetic azimuths. Thus the emerging RVM parameters reveal geometry of the emission region, not of the dipolar magnetic field. The results strongly support the vital role of nonbirefringent modal effects in radio pulsar profiles. Two proper modes may not be needed to explain observations of two orthogonal polarization tracks.

astro-ph.HE