GRB 180728A and SN 2018fip: the nearest high-energy cosmological gamma-ray burst with an associated supernova

Abstract

The long GRB 180728A, at a redshift of $z=0.1171$, stands out due to its high isotropic energy of $E_{\gamma ,iso}\sim 2.5\times 10^{51}$ erg, in contrast with most events at redshift $z<0.2$. We analyze the properties of GRB 180728A's prompt emission, afterglow, and associated supernova SN 2018fip, comparing them with other GRB-SN events. This study employs a dense photometric and spectroscopic follow-up of the afterglow and the SN up to 80 days after the burst, supported by image subtraction to remove the presence of a nearby bright star, and modelling of both the afterglow and the supernova. GRB 180728A lies on the $E_{p,i}-E_{\gamma ,iso}$ plane occupied by classical collapsar events, and the prompt emission is one of the most energetic at $z<0.2$ after GRB 030329 and GRB 221009A. The afterglow of GRB 180728A is less luminous than that of most long GRBs, showing a shallow early phase that steepens around 5 hours (0.2 days). The GRB exploded in an irregular, low-mass, blue, star-forming galaxy, typical of low-z collapsar events. Because of the relatively faint afterglow, the light curve bump of SN 2018fip dominates the optical emission already after $\sim$3 days and is one of the best sampled to date. The strong suppression below $\sim$ 4000 angstrom and a largely featureless continuum in the early 6--9 days spectra favor aspherical two-component ejecta with a high-velocity collimated component ($>20,000km{s}^{-1}$), dominant early-on, and a more massive, low-velocity component, which dominates at much later epochs. Our findings indicate that asymmetries need to be considered in order to better understand GRB-SNe. In any case, SN 2018fip shares many characteristics with typical GRB-SNe. Its kinetic energy is below the common range of $10^{52}-10^{53}$ erg and does not correlate with the high energy of the GRB, highlighting the diversity of the GRB-SN energy budget partition.

21 pages, 21 figures, 6 tables, submitted to Astronomy & Astrophysics

References in corpus (48)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Multi-messenger Observations of a Binary Neutron Star Merger
• The Supernova -- Gamma-Ray Burst Connection
• An online repository of Swift/XRT light curves of GRBs
• An optical supernova associated with the X-ray flash XRF 060218
• GROND - a 7-channel imager
• The Galaxy Population Hosting Gamma-Ray Bursts
• A neutron-star-driven X-ray flash associated with supernova SN 2006aj
• GRB Radiative Efficiencies Derived from the Swift Data: GRBs vs. XRFs, Long vs. Short
• REM observations of GRB 060418 and GRB 060607A: the onset of the afterglow and the initial fireball Lorentz factor determination
• Discovery of the nearby long, soft GRB 100316D with an associated supernova
• The Observable Signatures of GRB Cocoons
• The Dynamics and Afterglow Radiation of Gamma-Ray Bursts. I. Constant Density Medium
• A unified picture for low-luminosity and long gamma-ray bursts based on the extended progenitor of llgrb 060218/SN 2006aj
• Signatures of a jet cocoon in early spectra of a supernova associated with a $\gamma$-ray burst
• GRB 221009A, The BOAT
• The Ep,i - Eiso correlation: type I gamma-ray bursts and the new classification method
• The GRB 060218/SN 2006aj event in the context of other Gamma-Ray Burst Supernovae
• On the nature of nearby GRB/SN host galaxies
• An upper limit to the energy of gamma-ray bursts indicates that GRB/SNe are powered by magnetars
• Properties of the extremely energetic GRB~221009A from Konus-WIND and SRG/ART-XC observations
• Smooth Light Curves from a Bumpy Ride: Relativistic Blast Wave Encounters a Density Jump
• The peculiar short-duration GRB 200826A and its supernova
• Nebular spectra and abundance tomography of the type Ia supernova SN 2011fe: a normal SN Ia with a stable Fe core
• The GRB 030329 host: a blue low metallicity subluminous galaxy with intense star formation
• Diversity of GRB energetics vs. SN homogeneity: supernova 2013cq associated with the gamma-ray burst 130427A
• The Konus-Wind catalog of gamma-ray bursts with known redshifts. II. Waiting mode bursts simultaneously detected by Swift/BAT
• Extinction Corrected Star Formation Rates Empirically Derived from Ultraviolet-Optical Colors
• The first JWST spectrum of a GRB afterglow: No bright supernova in observations of the brightest GRB of all time, GRB 221009A
• 10.4m GTC observations of the nearby VHE-detected GRB 190829A/SN 2019oyw
• GRB jet structure and the jet break
• The optical light curve of GRB 221009A: the afterglow and the emerging supernova
• High-entropy ejecta plumes in Cassiopeia A from neutrino-driven convection
• GRB171010A / SN2017htp: a GRB-SN at z=0.33
• A Sensitive Search for Supernova Emission Associated with the Extremely Energetic and Nearby GRB 221009A
• Multiwavelength analysis of three SNe associated with GRBs observed by GROND
• Limit on Supernova Emission in the Brightest Gamma-ray Burst, GRB 221009A
• The quest for new correlations in the realm of the Gamma-Ray Burst -- Supernova connection
• The supernova of the MAGIC GRB190114C
• A blast from the infant Universe: the very high-z GRB 210905A
• Chemical stratification in a long gamma-ray burst cocoon and early-time spectral signatures of supernovae associated with gamma-ray bursts
• Combined X-ray and optical analysis to probe the origin of the plateau emission in $\gamma$-ray bursts afterglows
• Fires in the deep: The luminosity distribution of early-time gamma-ray-burst afterglows in light of the Gamow Explorer sensitivity requirements
• The brightest GRB ever detected: GRB 221009A as a highly luminous event at z = 0.151
• The Signature of Refreshed Shocks in the of Afterglow of GRB030329
• Highly luminous supernovae associated with gamma-ray bursts II. The luminous blue bump in the afterglow of GRB 140506A
• Diagnosing The Ejecta Properties of Engine-Driven Supernovae from Observables in Their Initial Phase
• A magnetar powers the luminous supernova 2023pel, associated with a long gamma-ray burst