Abstract
We present the localization and host galaxies of one repeating and two apparently nonrepeating fast radio bursts (FRBs). FRB 20180301A was detected and localized with the Karl G. Jansky Very ...Large Array to a star-forming galaxy at
z
= 0.3304. FRB20191228A and FRB20200906A were detected and localized by the Australian Square Kilometre Array Pathfinder to host galaxies at
z
= 0.2430 and
z
= 0.3688, respectively. We combine these with 13 other well-localized FRBs in the literature, and analyze the host galaxy properties. We find no significant differences in the host properties of repeating and apparently nonrepeating FRBs. FRB hosts are moderately star forming, with masses slightly offset from the star-forming main sequence. Star formation and low-ionization nuclear emission-line region emission are major sources of ionization in FRB host galaxies, with the former dominant in repeating FRB hosts. FRB hosts do not track stellar mass and star formation as seen in field galaxies (more than 95% confidence). FRBs are rare in massive red galaxies, suggesting that progenitor formation channels are not solely dominated by delayed channels which lag star formation by gigayears. The global properties of FRB hosts are indistinguishable from core-collapse supernovae and short gamma-ray bursts hosts, and the spatial offset (from galaxy centers) of FRBs is mostly inconsistent with that of the Galactic neutron star population (95% confidence). The spatial offsets of FRBs (normalized to the galaxy effective radius) also differ from those of globular clusters in late- and early-type galaxies with 95% confidence.
Abstract
We present Hubble Space Telescope ultraviolet and infrared observations of eight fast radio burst (FRB) host galaxies with subarcsecond localizations, including the hosts of three known ...repeating FRBs. We quantify their spatial distributions and locations with respect to their host galaxy light distributions, finding that they occur at moderate host-normalized offsets of 1.4
r
e
(0.6, 2.1
r
e
; 68% interval) and on fainter regions of their hosts in terms of IR light but overall trace the radial distribution of IR light in their galaxies. The FRBs in our tested distribution do not clearly trace the distributions of any other transient population with known progenitors and are statistically distinct from the locations of LGRBs, H-poor SLSNe, SGRBs, and Ca-rich transients. We further find that most FRBs are not in regions of elevated local star formation rates and stellar mass surface densities in comparison to the mean global values of their hosts. We also place upper limits on the IR flux at the FRB positions of
m
IR
≳ 24.8–27.6 AB mag, constraining both satellite and background galaxies to luminosities well below the host luminosity of FRB 121102. We find that 5/8 FRB hosts exhibit clear spiral arm features in IR light, and that the positions of all well-localized FRBs located in such hosts are consistent with their spiral arms, although not on their brightest regions. Our results do not strongly support the primary progenitor channel of FRBs being connected with either the most massive (stripped-envelope) stars or events that require kicks and long delay times (neutron star mergers).
Abstract
We present the Australian Square Kilometre Array Pathfinder localization and follow-up observations of the host galaxy of the repeating fast radio burst (FRB) source, FRB 20201124A, the ...fifth such extragalactic repeating FRB with an identified host. From spectroscopic observations using the 6.5 m MMT Observatory, we derive a redshift
z
= 0.0979 ± 0.0001, a star formation rate inferred from H
α
emission SFR(H
α
) ≈ 2.1
M
⊙
yr
−1
, and a gas-phase metallicity of 12+log(O/H) ≈ 9.0. By jointly modeling the 12 filter optical−mid-infrared (MIR) photometry and spectroscopy of the host, we infer a median stellar mass of ∼2 × 10
10
M
⊙
, internal dust extinction
A
V
≈ 1–1.5 mag, and a mass-weighted stellar population age of ∼5–6 Gyr. Connecting these data to the radio and X-ray observations, we cannot reconcile the broadband behavior with strong active galactic nucleus activity and instead attribute the dominant source of persistent radio emission to star formation, likely originating from the circumnuclear region of the host. The modeling also indicates a hot dust component contributing to the MIR luminosity at a level of ∼10%–30%. We model the host galaxy’s star formation and mass assembly histories, finding that the host assembled >90% of its mass by 1 Gyr ago and exhibited a fairly constant SFR for most of its existence, with no clear evidence of past starburst activity.
Abstract
We present the discovery of an as yet nonrepeating fast radio burst (FRB), FRB 20210117A, with the Australian Square Kilometre Array Pathfinder (ASKAP), as a part of the Commensal Real-time ...ASKAP Fast Transients Survey. The subarcsecond localization of the burst led to the identification of its host galaxy at
z
= 0.214(1). This redshift is much lower than what would be expected for a source dispersion measure (DM) of 729 pc cm
−3
, given typical contributions from the intergalactic medium and the host galaxy. Optical observations reveal the host to be a dwarf galaxy with little ongoing star formation—very different to the dwarf host galaxies of the known repeating FRBs 20121102A and 20190520B. We find an excess DM contribution from the host and attribute it to the FRB’s local environment. We do not find any radio emission from the FRB site or host galaxy. The low magnetized environment and the lack of a persistent radio source indicate that the FRB source is older than those found in other dwarf host galaxies, establishing the diversity of FRB sources in dwarf galaxy environments. We find our observations to be fully consistent with the “hypernebula” model, where the FRB is powered by an accretion jet from a hyperaccreting black hole. Finally, our high time resolution analysis reveals burst characteristics similar to those seen in repeating FRBs. We encourage follow-up observations of FRB 20210117A to establish any repeating nature.
Abstract
We present a systematic study of the most luminous (
M
IR
Vega magnitudes brighter than −14) infrared (IR) transients discovered by the
SPitzer
InfraRed Intensive Transients Survey (SPIRITS) ...between 2014 and 2018 in nearby galaxies (
D
< 35 Mpc). The sample consists of nine events that span peak IR luminosities of
M
4.5,peak
between −14 and −18.2, show IR colors between 0.2 < (3.6–4.5) < 3.0, and fade on timescales between 55 days <
t
fade
< 480 days. The two reddest events (
A
V
> 12) show multiple, luminous IR outbursts over several years and have directly detected, massive progenitors in archival imaging. With analyses of extensive, multiwavelength follow-up, we suggest the following possible classifications: five obscured core-collapse supernovae (CCSNe), two erupting massive stars, one luminous red nova, and one intermediate-luminosity red transient. We define a control sample of all optically discovered transients recovered in SPIRITS galaxies and satisfying the same selection criteria. The control sample consists of eight CCSNe and one Type Iax SN. We find that 7 of the 13 CCSNe in the SPIRITS sample have lower bounds on their extinction of 2 <
A
V
< 8. We estimate a nominal fraction of CCSNe in nearby galaxies that are missed by optical surveys as high as
(90% confidence). This study suggests that a significant fraction of CCSNe may be heavily obscured by dust and therefore undercounted in the census of nearby CCSNe from optical searches.
Abstract
We present a high-resolution analysis of the host galaxy of fast radio burst (FRB) 190608, an SB(r)c galaxy at
z
= 0.11778 (hereafter HG 190608), to dissect its local environment and its ...contributions to the FRB properties. Our Hubble Space Telescope Wide Field Camera 3 ultraviolet and visible light image reveals that the subarcsecond localization of FRB 190608 is coincident with a knot of star formation (Σ
SFR
= 1.5 × 10
−2
M
⊙
yr
−1
kpc
−2
) in the northwest spiral arm of HG 190608. Using H
β
emission present in our Keck Cosmic Web Imager integral field spectrum of the galaxy with a surface brightness of
μ
H
β
=
(
3.36
±
0.21
)
×
10
−
17
erg
s
−
1
cm
−
2
arcsec
−
2
, we infer an extinction-corrected H
α
surface brightness and compute a dispersion measure (DM) from the interstellar medium of HG 190608 of DM
Host,ISM
= 94 ± 38 pc cm
−3
. The galaxy rotates with a circular velocity
v
circ
= 141 ± 8 km s
−1
at an inclination
i
gas
= 37° ± 3°, giving a dynamical mass
M
halo
dyn
≈
10
11.96
±
0.08
M
⊙
. This implies a halo contribution to the DM of DM
Host,Halo
= 55 ± 25 pc cm
−3
subject to assumptions on the density profile and fraction of baryons retained. From the galaxy rotation curve, we infer a bar-induced pattern speed of Ω
p
= 34 ± 6 km s
−1
kpc
−1
using linear resonance theory. We then calculate the maximum time since star formation for a progenitor using the furthest distance to the arm’s leading edge within the localization, and find
t
enc
=
21
−
6
+
25
Myr. Unlike previous high-resolution studies of FRB environments, we find no evidence of disturbed morphology, emission, or kinematics for FRB 190608.
We present HST/WFC3 ultraviolet imaging in the F275W and F336W bands of the Type IIb SN 2001ig at an age of more than 14 years. A clear point source is detected at the site of the explosion, with ...mF275W = 25.39 0.10 and mF336W = 25.88 0.13 mag. Despite weak constraints on both the distance to the host galaxy NGC 7424 and the line-of-sight reddening to the supernova, this source matches the characteristics of an early B-type main-sequence star with 19,000 < Teff < 22,000 K and . A BPASS v2.1 binary evolution model, with primary and secondary masses of 13 M and 9 M , respectively, is found to simultaneously resemble, in the Hertzsprung-Russell diagram, both the observed location of this surviving companion, and the primary star evolutionary endpoints for other Type IIb supernovae. This same model exhibits highly variable late-stage mass loss, as expected from the behavior of the radio light curves. A Gemini/GMOS optical spectrum at an age of 6 years reveals a narrow He ii λ4686 emission line, indicative of continuing interaction with a dense circumstellar medium at large radii from the progenitor. We review our findings on SN 2001ig in the context of binary evolution channels for stripped-envelope supernovae. Owing to the uncrowded nature of its environment in the ultraviolet, this study of SN 2001ig represents one of the cleanest detections to date of a surviving binary companion to a Type IIb supernova.
Disentangling the Cosmic Web toward FRB 190608 Simha, Sunil; Burchett, Joseph N.; Prochaska, J. Xavier ...
Astrophysical journal/The Astrophysical journal,
10/2020, Letnik:
901, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Fast radio burst (FRB) 190608 was detected by the Australian Square Kilometre Array Pathfinder (ASKAP) and localized to a spiral galaxy at in the Sloan Digital Sky Survey (SDSS) footprint. The burst ...has a large dispersion measure ( ) compared to the expected cosmic average at its redshift. It also has a large rotation measure ( ) and scattering timescale (τ = 3.3 ms at 1.28 GHz). Chittidi et al. perform a detailed analysis of the ultraviolet and optical emission of the host galaxy and estimate the host DM contribution to be . This work complements theirs and reports the analysis of the optical data of galaxies in the foreground of FRB 190608 in order to explore their contributions to the FRB signal. Together, the two studies delineate an observationally driven, end-to-end study of matter distribution along an FRB sightline, the first study of its kind. Combining our Keck Cosmic Web Imager (KCWI) observations and public SDSS data, we estimate the expected cosmic dispersion measure along the sightline to FRB 190608. We first estimate the contribution of hot, ionized gas in intervening virialized halos ( ). Then, using the Monte Carlo Physarum Machine methodology, we produce a 3D map of ionized gas in cosmic web filaments and compute the DM contribution from matter outside halos ( ). This implies that a greater fraction of ionized gas along this sightline is extant outside virialized halos. We also investigate whether the intervening halos can account for the large FRB rotation measure and pulse width and conclude that it is implausible. Both the pulse broadening and the large Faraday rotation likely arise from the progenitor environment or the host galaxy.
We present observations and detailed characterizations of five new host galaxies of fast radio bursts (FRBs) discovered with the Australian Square Kilometre Array Pathfinder (ASKAP) and localized to ...1″. Combining these galaxies with FRB hosts from the literature, we introduce criteria based on the probability of chance coincidence to define a subsample of 10 highly confident associations (at z = 0.03-0.52), 3 of which correspond to known repeating FRBs. Overall, the FRB-host galaxies exhibit a broad, continuous range of color (Mu − Mr = 0.9-2.0), stellar mass (M = 108 − 6 × 1010 M ), and star formation rate (SFR = 0.05-10 M yr−1) spanning the full parameter space occupied by z < 0.5 galaxies. However, they do not track the color-magnitude, SFR-M , nor BPT diagrams of field galaxies surveyed at similar redshifts. There is an excess of "green valley" galaxies and an excess of emission-line ratios indicative of a harder radiation field than that generated by star formation alone. From the observed stellar mass distribution, we rule out the hypothesis that FRBs strictly track stellar mass in galaxies (>99% c.l.). We measure a median offset of 3.3 kpc from the FRB to the estimated center of the host galaxies and compare the host-burst offset distribution and other properties with the distributions of long- and short-duration gamma-ray bursts (LGRBs and SGRBs), core-collapse supernovae (CC-SNe), and SNe Ia. This analysis rules out galaxies hosting LGRBs (faint, star-forming galaxies) as common hosts for FRBs (>95% c.l.). Other transient channels (SGRBs, CC-, and SNe Ia) have host-galaxy properties and offsets consistent with the FRB distributions. All of the data and derived quantities are made publicly available on a dedicated website and repository.
A Search for the Host Galaxy of FRB 171020 Mahony, Elizabeth K.; Ekers, Ron D.; Macquart, Jean-Pierre ...
Astrophysical journal. Letters,
11/2018, Letnik:
867, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We report on a search for the host galaxy of FRB 171020, the fast radio burst (FRB) with the smallest recorded dispersion measure (DM; DM = 114 pc cm−3) of our ongoing ASKAP survey. The low DM ...confines the burst location within a sufficiently small volume to rigorously constrain the identity of the host galaxy. We identify 16 candidate galaxies in the search volume and single out ESO 601-G036, an Sc galaxy at redshift z = 0.00867, as the most likely host galaxy. Ultraviolet and optical imaging and spectroscopy reveal that this galaxy has a star formation rate of approximately 0.1 M yr−1 and oxygen abundance 12 + log(O/H) = 8.3 0.2, properties that are remarkably consistent with the galaxy hosting the repeating FRB 121102. However, in contrast to FRB 121102, follow-up radio observations of ESO 601-G036 show no compact radio emission above a 5 limit of L2.1GHz = 3.6 × 1019 W Hz−1. Using radio continuum observations of the field, combined with archival optical imaging data, we find no analog to the persistent radio source associated with FRB 121102 within the localization region of FRB 171020 out to z = 0.06. These results suggest that FRBs are not necessarily associated with a luminous and compact radio continuum source.
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