12 research outputs found
How limiting is optical follow-up for fast radio burst applications? Forecasts for radio and optical surveys
Fast radio bursts (FRBs) are the first cosmological radio sources that vary
on millisecond timescales, which makes them a unique probe of the Universe.
Many proposed applications of FRBs require associated redshifts. These can only
be obtained by localizing FRBs to their host galaxies and subsequently
measuring their redshifts. Upcoming FRB surveys will provide arcsecond
localization for many FRBs, not all of which can be followed up with dedicated
optical observations. We aim to estimate the fraction of FRB hosts that will be
catalogued with redshifts by existing and future optical surveys. We use the
population synthesis code frbpoppy to simulate several FRB surveys, and the
semi-analytical galaxy formation code GALFORM to simulate their host galaxies.
We obtain redshift distributions for the simulated FRBs and the fraction with
host galaxies in a survey. Depending on whether FRBs follow the cosmic star
formation rate or stellar mass, 20 to 40 per cent of CHIME FRB hosts will be
observed in an SDSS-like survey, all at . The deeper DELVE survey will
detect 63 to 85 per cent of ASKAP FRBs found in its coherent search mode. CHIME
FRBs will reach , SKA1-Mid FRBs , but ground based follow-up
is limited to . We discuss consequences for several FRB
applications. If of ASKAP FRBs have measured redshifts, 1000 detected
FRBs can be used to constrain to within per
cent at 95 per cent credibility. We provide strategies for optimized follow-up,
when building on data from existing surveys. Data and codes are made available.Comment: 18 pages, 16 figures, 4 tables, accepted for publication in MNRAS.
Code available at https://github.com/JoschaJ/mockFRBhost
No Radio Bursts Detected from FIRST J141918.9+394036 in Green Bank Telescope Observations
Precise localization of the first-known repeating fast radio burst source, FRB 121102 (Spitler et al. 2016; Chatterjee et al. 2017), led to its association with a star-forming region inside a low-metallicity dwarf host galaxy (Tendulkar et al. 2017). This host environment is similar to that typically associated with long gamma-ray bursts (GRB) and superluminous supernovae, potentially linking these astrophysical phenomena (Metzger et al. 2017). In addition, the bursting source is found to be spatially coincident with a compact (< 0.7 pc; Marcote et al. 2017), persistent radio source (Chatterjee et al. 2017). Ofek (2017) identified similar radio sources in the Very Large Array FIRST survey (Becker et al. 1995). One of these sources, FIRST J141918.9+394036 (hereafter FIRST J1419+3940), was identified as a radio transient decaying in brightness by a factor of ~50 over several decades (Law et al. 2018). Very-long-baseline radio interferometric observations support the theory that FIRST J1419+3940 is the afterglow of a long GRB, based on the inferred physical size of the emission region (1.6 ± 0.3 pc; Marcote et al. 2019)
No Radio Bursts Detected from FIRST J141918.9+394036 in Green Bank Telescope Observations
Precise localization of the first-known repeating fast radio burst source, FRB 121102 (Spitler et al. 2016; Chatterjee et al. 2017), led to its association with a star-forming region inside a low-metallicity dwarf host galaxy (Tendulkar et al. 2017). This host environment is similar to that typically associated with long gamma-ray bursts (GRB) and superluminous supernovae, potentially linking these astrophysical phenomena (Metzger et al. 2017). In addition, the bursting source is found to be spatially coincident with a compact (< 0.7 pc; Marcote et al. 2017), persistent radio source (Chatterjee et al. 2017). Ofek (2017) identified similar radio sources in the Very Large Array FIRST survey (Becker et al. 1995). One of these sources, FIRST J141918.9+394036 (hereafter FIRST J1419+3940), was identified as a radio transient decaying in brightness by a factor of ~50 over several decades (Law et al. 2018). Very-long-baseline radio interferometric observations support the theory that FIRST J1419+3940 is the afterglow of a long GRB, based on the inferred physical size of the emission region (1.6 ± 0.3 pc; Marcote et al. 2019)
Limits on Enhanced Radio Wave Scattering by Supernova Remnants
We report multifrequency observations with the NRAO Very Long Baseline Array
(VLBA) of the compact radio sources J0128+6306 and J0547+2721, which are viewed
through the supernova remnants G127.1+0.5 and S147, respectively. Observations
were made at frequencies of 1.427, 1.667, 2.271, and 4.987 GHz. The lines of
sight to these sources pass through the shock wave and upstream and downstream
turbulent layers of their respective supernova remnants, and thus might detect
cosmic-ray generated turbulence produced during the Fermi acceleration process.
For both sources, we detect interstellar scattering, characterized by a
component of the angular size which scales as the square of the observing
wavelength. The magnitude of the scattering is characterized by an effective
scattering angular size theta_S0 at a frequency of 1 GHz of 13.2 +/- 2.6
milliarcseconds (mas) for J0128+6306 and 6.7 +/- 2.2 mas for J0547+2721. These
angular sizes are consistent with the ``incidental'' scattering for any line of
sight out of the galaxy at similar galactic latitudes and longitudes. There is
therefore no evidence for enhanced turbulence at these supernova remnants. We
establish upper limits to the supernova remnant-associated scattering measures
of 8.1-14.8 m^-20/3-pc for J0128+6306 and 3.0 m^-20/3-pc for J0547+2721.Comment: To be published in ApJ, 25 pages, 4 figures, 2 table
The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102
The precise localization of the repeating fast radio burst (FRB 121102) has
provided the first unambiguous association (chance coincidence probability
) of an FRB with an optical and persistent radio
counterpart. We report on optical imaging and spectroscopy of the counterpart
and find that it is an extended ()
object displaying prominent Balmer and [OIII] emission lines. Based on the
spectrum and emission line ratios, we classify the counterpart as a
low-metallicity, star-forming, AB mag dwarf galaxy at a
redshift of , corresponding to a luminosity distance of 972 Mpc.
From the angular size, the redshift, and luminosity, we estimate the host
galaxy to have a diameter kpc and a stellar mass of
, assuming a mass-to-light ratio between 2 to
3. Based on the H flux, we estimate the star
formation rate of the host to be and a
substantial host dispersion measure depth .
The net dispersion measure contribution of the host galaxy to FRB 121102 is
likely to be lower than this value depending on geometrical factors. We show
that the persistent radio source at FRB 121102's location reported by Marcote
et al (2017) is offset from the galaxy's center of light by 200 mas and
the host galaxy does not show optical signatures for AGN activity. If FRB
121102 is typical of the wider FRB population and if future interferometric
localizations preferentially find them in dwarf galaxies with low metallicities
and prominent emission lines, they would share such a preference with long
gamma ray bursts and superluminous supernovae.Comment: 12 pages, 3 figures, Published in ApJ Letters. V2: Corrected mistake
in author lis
Multiwavelength Constraints on the Origin of a Nearby Repeating Fast Radio Burst Source in a Globular Cluster
Since fast radio bursts (FRBs) were discovered, their precise origins have
remained a mystery. Multiwavelength observations of nearby FRB sources provide
one of the best ways to make rapid progress in our understanding of the
enigmatic FRB phenomenon. We present results from a sensitive, broadband
multiwavelength X-ray and radio observational campaign of FRB 20200120E, the
closest known extragalactic repeating FRB source. At a distance of 3.63 Mpc,
FRB 20200120E resides in an exceptional location, within a ~10 Gyr-old globular
cluster in the M81 galactic system. We place deep limits on both the persistent
X-ray luminosity and prompt X-ray emission at the time of radio bursts from FRB
20200120E, which we use to constrain possible progenitors for the source. We
compare our results to various classes of X-ray sources and transients. In
particular, we find that FRB 20200120E is unlikely to be associated with:
ultraluminous X-ray bursts (ULXBs), similar to those observed from objects of
unknown origin in other extragalactic globular clusters; giant flares, like
those observed from Galactic and extragalactic magnetars; or most intermediate
flares and very bright short X-ray bursts, similar to those seen from magnetars
in the Milky Way. We show that FRB 20200120E is also unlikely to be powered by
a persistent or transient ultraluminous X-ray (ULX) source or a young,
extragalactic pulsar embedded in a Crab-like nebula. We also provide new
constraints on the compatibility of FRB 20200120E with accretion-based FRB
models involving X-ray binaries and models that require a synchrotron maser
process from relativistic shocks to generate FRB emission. These results
highlight the power that multiwavelength observations of nearby FRBs can
provide for discriminating between potential FRB progenitor models.Comment: 58 pages, 10 figures, 7 tables, submitte
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