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Register a new userSearch for transient gravitational wave signals associated with magnetar bursts during Advanced LIGOs second observing run
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We present the results of a search for short and intermediate-duration gravitational-wave signals from four magnetar bursts in Advanced LIGOs second observing run. We find no evidence of a signal and set upper bounds on the root sum squared of the total dimensionless strain ($h_{text{rss}}$) from incoming intermediate-duration gravitational waves ranging from $1.1 times 10^{-22}$ at 150 Hz to $4.4 times 10^{-22}$ at 1550 Hz at 50% detection efficiency. From the known distance to the magnetar SGR 1806-20 (8.7 kpc) we can place upper bounds on the isotropic gravitational wave energy of $3.4 times 10^{44} text{erg}$ at 150 Hz assuming optimal orientation. This represents an improvement of about a factor of 10 in strain sensitivity from the previous search for such signals, conducted during initial LIGOs sixth science run. The short duration search yielded upper limits of $2.1 times 10^{44} ,text{erg}$ for short white noise bursts, and $2.3times 10^{47},text{erg}$ for $100 , text{ms}$ long ringdowns at 1500 Hz, both at 50% detection efficiency.
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We present the results of targeted searches for gravitational-wave transients associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from 2016 November to 2017 August. We have analyzed 98 gamma-ray bursts using an unmodeled search method that searches for generic transient gravitational waves and 42 with a modeled search method that targets compact-binary mergers as progenitors of short gamma-ray bursts. Both methods clearly detect the previously reported binary merger signal GW170817, with p-values of $<9.38 times 10^{-6}$ (modeled) and $3.1 times 10^{-4}$ (unmodeled). We do not find any significant evidence for gravitational-wave signals associated with the other gamma-ray bursts analyzed, and therefore we report lower bounds on the distance to each of these, assuming various source types and signal morphologies. Using our final modeled search results, short gamma-ray burst observations, and assuming binary neutron star progenitors, we place bounds on the rate of short gamma-ray bursts as a function of redshift for $z leq 1$. We estimate 0.07-1.80 joint detections with Fermi-GBM per year for the 2019-20 LIGO-Virgo observing run and 0.15-3.90 per year when current gravitational-wave detectors are operating at their design sensitivities.
Progenitor scenarios for short gamma-ray bursts (short GRBs) include coalescenses of two neutron stars or a neutron star and black hole, which would necessarily be accompanied by the emission of strong gravitational waves. We present a search for these known gravitational-wave signatures in temporal and directional coincidence with 22 GRBs that had sufficient gravitational-wave data available in multiple instruments during LIGOs fifth science run, S5, and Virgos first science run, VSR1. We find no statistically significant gravitational-wave candidates within a [-5, +1) s window around the trigger time of any GRB. Using the Wilcoxon-Mann-Whitney U test, we find no evidence for an excess of weak gravitational-wave signals in our sample of GRBs. We exclude neutron star-black hole progenitors to a median 90% CL exclusion distance of 6.7 Mpc.
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The Fermi Gamma-ray Burst Monitor Team
, The LIGO Scientificn Collaboration
, the Virgo Collaboration: E. Burns
2018
We present a search for prompt gamma-ray counterparts to compact binary coalescence gravitational wave (GW) candidates from Advanced LIGOs first observing run (O1). As demonstrated by the multimessenger observations of GW170817/GRB 170817A, electromagnetic and GW observations provide complementary information about the astrophysical source and, in the case of weaker candidates, may strengthen the case for an astrophysical origin. Here we investigate low-significance GW candidates from the O1 compact-binary coalescence searches using the Fermi Gamma-ray Burst Monitor (GBM), leveraging its all-sky and broad energy coverage. Candidates are ranked and compared to background to measure significance. Those with false alarm rates of less than 10^-5 Hz (about one per day) are used as the search sample for gamma-ray follow-up. No GW candidates were found to be coincident with gamma-ray transients independently identified by blind searches of the GBM data. In addition, GW candidate event times were followed up by a separate targeted search of GBM data. Among the resulting GBM events, the two with lowest false alarm rates were the gamma-ray transient GW150914-GBM presented in Connaughton et al. (2016) and a solar flare in chance coincidence with a GW candidate.
We present an Advanced LIGO and Advanced Virgo search for sub-solar mass ultracompact objects in data obtained during Advanced LIGOs second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational wave candidates consistent with sub-solar mass ultracompact binaries with at least one component between 0.2 - 1.0 solar masses. We use the null result to constrain the binary merger rate of (0.2 solar mass, 0.2 solar mass) binaries to be less than 3.7 x 10^5 Gpc^-3 yr^-1 and the binary merger rate of (1.0 solar mass, 1.0 solar mass) binaries to be less than 5.2 x 10^3 Gpc^-3 yr^-1. Sub-solar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with sub-solar masses. Assuming a particular primordial black hole formation model, we constrain a population of merging 0.2 solar mass black holes to account for less than 16% of the dark matter density and a population of merging 1.0 solar mass black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict sub-solar mass binaries.
We present the results of the search for gravitational waves (GWs) associated with $gamma$-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 $gamma$-ray bursts for which LIGO data are available with sufficient duration. For all $gamma$-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of $10^{-2}M_odot c^2$ were emitted within the $16$-$500,$Hz band, and we find a median 90% confidence limit of 71$,$Mpc at 150$,$Hz. For the subset of 19 short/hard $gamma$-ray bursts, we place lower bounds on distance with a median 90% confidence limit of 90$,$Mpc for binary neutron star (BNS) coalescences, and 150 and 139$,$Mpc for neutron star-black hole coalescences with spins aligned to the orbital angular momentum and in a generic configuration, respectively. These are the highest distance limits ever achieved by GW searches. We also discuss in detail the results of the search for GWs associated with GRB 150906B, an event that was localized by the InterPlanetary Network near the local galaxy NGC 3313, which is at a luminosity distance of 54$,$Mpc ($z=0.0124$). Assuming the $gamma$-ray emission is beamed with a jet half-opening angle $leq 30^{circ}$, we exclude a BNS and a neutron star-black hole in NGC 3313 as the progenitor of this event with confidence $>99$%. Further, we exclude such progenitors up to a distance of 102$,$Mpc and 170$,$Mpc, respectively.
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