The short GRB070707 afterglow and its very faint host galaxy

Abstract

We present the results from an ESO/VLT campaign aimed at studying the afterglow properties of the short/hard gamma ray burst GRB 070707. Observations were carried out at ten different epochs from ~0.5 to ~80 days after the event. The optical flux decayed steeply with a power-law decay index greater than 3, later levelling off at R~27.3 mag; this is likely the emission level of the host galaxy, the faintest yet detected for a short GRB. Spectroscopic observations did not reveal any line features/edges that could unambiguously pinpoint the GRB redshift, but set a limit z < 3.6. In the range of allowed redshifts, the host has a low luminosity, comparable to that of long-duration GRBs. The existence of such faint host galaxies suggests caution when associating short GRBs with bright, offset galaxies, where the true host might just be too dim for detection. The steepness of the decay of the optical afterglow of GRB 070707 challenges external shock models for the optical afterglow of short/hard GRBs. We argue that this behaviour might results from prolonged activity of the central engine or require alternative scenarios.

arXiv comment6 pages, 5 figures, accepted by A&A

References in corpus (48)

• Physical processes shaping GRB X-ray afterglow lightcurves: theoretical implications from the Swift XRT observations
• Short-Hard Gamma-Ray Bursts
• Long gamma-ray bursts and core-collapse supernovae have different environments
• The Dynamics and Light Curves of Beamed Gamma Ray Burst Afterglows
• A short gamma-ray burst apparently asssociated with an elliptical galaxy at redshift z=0.225
• An exceptionally bright flare from SGR1806-20 and the origins of short-duration gamma-ray bursts
• The Ep,i - Eiso correlation in GRBs: updated observational status, re-analysis and main implications
• No supernovae associated with two long-duration gamma ray bursts
• An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova
• The gamma-ray burst GRB060614 requires a novel explosive process
• Measuring the cosmological parameters with the Ep,i-Eiso correlation of Gamma-Ray Bursts
• The afterglow and elliptical host galaxy of the short gamma-ray burst GRB 050724
• An origin for short g-ray bursts unassociated with current star formation
• The Progenitors of Short Gamma-Ray Bursts
• A Study of Compact Object Mergers as Short Gamma-ray Burst Progenitors
• The optical afterglow of the short gamma-ray burst GRB 050709
• The Afterglows of Swift-era Gamma-Ray Bursts II.: Type I GRB versus Type II GRB Optical Afterglows
• Signatures of Extragalactic Dust in pre-Swift GRB Afterglows
• A New Population of High Redshift Short-Duration Gamma-Ray Bursts
• The evolution of the luminosity functions in the FORS Deep Field from low to high redshift: I. The blue bands
• Short gamma-ray bursts from binary neutron star mergers in globular clusters
• The Host Galaxies of Short-Duration Gamma-Ray Bursts: Luminosities, Metallicities, and Star Formation Rates
• The Integral Burst Alert System (IBAS)
• The BATSE-Swift luminosity and redshift distributions of short-duration GRBs
• A Complete Survey of the Transient Radio Sky and Implications for Gamma-Ray Bursts, Supernovae, and other Relativistic Explosions
• An origin in the local Universe for some short gamma-ray bursts
• The Luminosity and Redshift Distributions of Short-Duration GRB
• A Morphological Study of Gamma-Ray Burst Host Galaxies
• Evolution of the Color-Magnitude relation in High-Redshift Clusters: Early-type Galaxies in the Lynx Supercluster at z~1.26
• Short GRBs and Mergers of Compact Objects: Observational Constraints
• A Giant Flare from a Soft Gamma Repeater in the Andromeda Galaxy, M31
• Optical emission from GRB 050709: a short/hard GRB in a star forming galaxy
• On the Possibility of Identification of a Short/Hard Burst GRB 051103 with the Giant Flare from a Soft Gamma Repeater in the M81 Group of Galaxies
• A Putative Early-Type Host Galaxy for GRB 060502B: Implications for the Progenitors of Short-Duration Hard-Spectrum Bursts
• Jets, Structured Outflows, and Energy Injection in GRB Afterglows: Numerical Modelling
• The Prompt Gamma-Ray and Afterglow Energies of Short-Duration Gamma-Ray Bursts
• No Universality for Electron's Power-Law Index (p) in Gamma-Ray Bursts and Other Relativistic Sources
• Multicolor observations of the afterglow of the short/hard GRB 050724
• A case of mistaken identity? GRB 060912A and the nature of the long -- short GRB divide
• Merger Sites of Double Neutron Stars and their Host Galaxies
• Short Gamma Ray Bursts: a bimodal origin?
• The redshift distribution of short gamma-ray bursts from dynamically formed neutron star binaries
• GRB Fireball Physics: Prompt and Early Emission
• Short Hard Gamma Ray Bursts And Their Afterglows
• Velocity dispersions and cluster properties in the SARS (Southern Abell Redshift Survey) clusters. Paper II
• GRB 070707: the first short gamma-ray burst observed by INTEGRAL
• Blob ejection from advection-dominated accretion flow: observational consequences
• Long gamma-ray bursts without visible supernovae: a case study of redshift estimators and alleged novel objects

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• GRB 080503: Implications of a Naked Short Gamma-Ray Burst Dominated by Extended Emission
• A Short GRB "No-Host'' Problem? Investigating Large Progenitor Offsets for Short GRBs with Optical Afterglows
• A Comprehensive Study of Gamma-Ray Burst Optical Emission: I. Flares and Early Shallow Decay Component
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• Revisiting the Long/Soft-Short/Hard Classification of Gamma-Ray Bursts in the Fermi Era
• The Environments of Short-Duration Gamma-Ray Bursts and Implications for their Progenitors
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• Discovery of the Very Red Near-Infrared and Optical Afterglow of the Short-Duration GRB 070724A
• Statistical classification of gamma-ray bursts based on the Amati relation
• A search for optical and near-infrared counterparts of the compact binary merger GW190814
• Probing Kilonova Ejecta Properties Using a Catalog of Short Gamma-Ray Burst Observations
• The Unprecedented Properties of the First Electromagnetic Counterpart to a Gravitational Wave Source
• Exploring compact binary merger host galaxies and environments with $\mathrm{zELDA}$
• GRB 071227: an additional case of a disguised short burst
• The afterglow and host galaxy of GRB 090205: evidence for a Ly-alpha emitter at z=4.65
• A short gamma-ray burst from a proto-magnetar remnant
• Fundamental physics from black holes, neutron stars and gamma-ray bursts
• On the offset of Short Gamma-ray Bursts
• Host galaxies and electromagnetic counterparts to binary neutron star mergers across the cosmic time: Detectability of GW170817-like events