Searches for optical transients are usually performed with a cadence of days to weeks, optimized for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on the detection of extragalactic transients evolving at sub-hour time-scales. Here, we present the results of deep searches for dim, minute-time-scale extragalactic fast transients using the Dark Energy Camera, a core facility of our all-wavelength and all-messenger Deeper, Wider, Faster programme. We used continuous 20 s exposures to systematically probe time-scales down to 1.17 min at magnitude limits g > 23 (AB), detecting hundreds of transient and variable sources. Nine candidates passed our strict criteria on duration and non-stellarity, all of which could be classified as flare stars based on deep multiband imaging. Searches for fast radio burst and gamma-ray counterparts during simultaneous multifacility observations yielded no counterparts to the optical transients. Also, no long-term variability was detected with pre-imaging and follow-up observations using the SkyMapper optical telescope. We place upper limits for minute-time-scale fast optical transient rates for a range of depths and time-scales. Finally, we demonstrate that optical g-band light-curve behaviour alone cannot discriminate between confirmed extragalactic fast transients such as prompt GRB flashes and Galactic stellar flares.

Andreoni, I., Cooke, J., Webb, S., Rest, A., Pritchard, T., Caleb, M., et al. (2020). Probing the extragalactic fast transient sky at minute time-scales with DECam. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Volume 491(4 (February 2020)), 5852-5866 [10.1093/mnras/stz3381].

Probing the extragalactic fast transient sky at minute time-scales with DECam

Ravasio, M. E.;
2020

Abstract

Searches for optical transients are usually performed with a cadence of days to weeks, optimized for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on the detection of extragalactic transients evolving at sub-hour time-scales. Here, we present the results of deep searches for dim, minute-time-scale extragalactic fast transients using the Dark Energy Camera, a core facility of our all-wavelength and all-messenger Deeper, Wider, Faster programme. We used continuous 20 s exposures to systematically probe time-scales down to 1.17 min at magnitude limits g > 23 (AB), detecting hundreds of transient and variable sources. Nine candidates passed our strict criteria on duration and non-stellarity, all of which could be classified as flare stars based on deep multiband imaging. Searches for fast radio burst and gamma-ray counterparts during simultaneous multifacility observations yielded no counterparts to the optical transients. Also, no long-term variability was detected with pre-imaging and follow-up observations using the SkyMapper optical telescope. We place upper limits for minute-time-scale fast optical transient rates for a range of depths and time-scales. Finally, we demonstrate that optical g-band light-curve behaviour alone cannot discriminate between confirmed extragalactic fast transients such as prompt GRB flashes and Galactic stellar flares.
Articolo in rivista - Articolo scientifico
stars: flare; gamma-ray burst: general; supernovae: general; radio continuum: transients; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Astrophysics of Galaxies; Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - Solar and Stellar Astrophysics;
English
4-dic-2019
2020
Volume 491
4 (February 2020)
5852
5866
reserved
Andreoni, I., Cooke, J., Webb, S., Rest, A., Pritchard, T., Caleb, M., et al. (2020). Probing the extragalactic fast transient sky at minute time-scales with DECam. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Volume 491(4 (February 2020)), 5852-5866 [10.1093/mnras/stz3381].
File in questo prodotto:
File Dimensione Formato  
1903.11083.pdf

Solo gestori archivio

Tipologia di allegato: Submitted Version (Pre-print)
Dimensione 4.08 MB
Formato Adobe PDF
4.08 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/269027
Citazioni
  • Scopus 26
  • ???jsp.display-item.citation.isi??? 23
Social impact