Habitat Selection by Chiricahua Leopard Frogs During Summer Monsoons

One-third of the described species of amphibians worldwide are threatened with extinction, including the Chiricahua leopard frog (Lithobates chiricahuensis).  This frog is highly aquatic, found in portions of Arizona and New Mexico, and listed as threatened under the Endangered Species Act.  Currently, the Chiricahua leopard frog is restricted to anthropogenic sources of water, including tanks maintained for livestock, throughout most of its range.  Movement habits of this frog and patterns of dispersal between disjunct water sources are not well understood.  We attached radio transmitters to 44 total frogs on the Ladder Ranch in southern New Mexico during summer 2014 and located each frog daily for up to 8 weeks (mean = 29 days).  We quantified habitat characteristics at each frog location and a random location 5 meters away.  We assessed fine-scale habitat selection using conditional logistic regression and also explored the degree of variation in selection among individual frogs.  Frogs chose areas with more low-lying cover (especially aquatic vegetation and woody debris), less overstory cover, and a mud substrate.  Whether the location was far from or close to water and the amount of overstory cover did not appear to be important for selection, suggesting that frogs are able to find areas that provide habitat away from water One-third of the described species of amphibians worldwide are threatened with extinction, including the Chiricahua leopard frog (Lithobates chiricahuensis).  This frog is highly aquatic, found in portions of Arizona and New Mexico, and listed as threatened under the Endangered Species Act.  Currently, the Chiricahua leopard frog is restricted to anthropogenic sources of water, including tanks maintained for livestock, throughout most of its range.  Movement habits of this frog and patterns of dispersal between disjunct water sources are not well understood.  We attached radio transmitters to 44 total frogs on the Ladder Ranch in southern New Mexico during summer 2014 and located each frog daily for up to 8 weeks (mean = 29 days).  We quantified habitat characteristics at each frog location and a random location 5 meters away.  We assessed fine-scale habitat selection using conditional logistic regression and also explored the degree of variation in selection among individual frogs.  Frogs chose areas with more low-lying cover (especially aquatic vegetation and woody debris), less overstory cover, and a mud substrate. Whether the location was far from or close to water and the amount of overstory cover did not appear to be important for selection, suggesting that frogs are able to find areas that provide habitat away from water bodies.  The variation among individuals was low, suggesting that tracked were selecting similar habitat characteristics. The findings of this study will inform active management of amphibians in anthropogenic settings, where managers can enhance amphibian habitat characteristics between occupied sites to improve population connectivity

Understanding Movement Patterns of Chiricahua Leopard Frogs to Promote Species Persistence in Desert Ecosystems

One-third of the described species of amphibians worldwide are threatened with extinction, including the Chiricahua leopard frog (Lithobates chiricahuensis). This frog is highly aquatic, found in portions of Arizona and New Mexico, and listed as threatened under the Endangered Species Act. Currently, habitat for the Chiricahua leopard frog generally is restricted to anthropogenic sources of water, including tanks maintained for livestock. Movement habits of this frog and patterns of dispersal between disjunct water sources are not well understood. On the Ladder Ranch, a working bison ranch in southern New Mexico, we constructed pitfall traps to capture frogs leaving stock tanks. We attached radio transmitters to 14 individuals during the summer of 2013 to study the potential for movement between widely-spaced tanks. Individuals captured in stock tanks (n = 11) showed very high site fidelity, never leaving their source location while carrying transmitters up to 18 days. Individuals captured in a nearby creek (n = 3) moved as much as 2800 m over a 17-day period. Daily movements of these individuals varied greatly (mean = 121 m, SD = 249) and do not appear to be related to temperature or precipitation. During the 2014 field season, we will attempt to track a larger number of animals moving along the creek corridor and to nearby tanks. Quantifying movement abilities of native amphibians will allow biologists to manage anthropogenic water sources to support movement between habitat patches and maintain functioning metapopulations, while preserving important features of the Ranch for livestock use

A nonlinear scalar model of extreme mass ratio inspirals in effective field theory I. Self force through third order

The motion of a small compact object in a background spacetime is investigated in the context of a model nonlinear scalar field theory. This model is constructed to have a perturbative structure analogous to the General Relativistic description of extreme mass ratio inspirals (EMRIs). We apply the effective field theory approach to this model and calculate the finite part of the self force on the small compact object through third order in the ratio of the size of the compact object to the curvature scale of the background (e.g., black hole) spacetime. We use well-known renormalization methods and demonstrate the consistency of the formalism in rendering the self force finite at higher orders within a point particle prescription for the small compact object. This nonlinear scalar model should be useful for studying various aspects of higher-order self force effects in EMRIs but within a comparatively simpler context than the full gravitational case. These aspects include developing practical schemes for higher order self force numerical computations, quantifying the effects of transient resonances on EMRI waveforms and accurately modeling the small compact object's motion for precise determinations of the parameters of detected EMRI sources.Comment: 30 pages, 8 figure

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

Erratum: “Searches for Gravitational Waves from Known Pulsars at Two Harmonics in 2015–2017 LIGO Data” (2019, ApJ, 879, 10)

Due to an error at the publisher, in the published article the number of pulsars presented in the paper is incorrect in multiple places throughout the text. Specifically, "222" pulsars should be "221." Additionally, the number of pulsars for which we have EM observations that fully overlap with O1 and O2 changes from "168" to "167." Elsewhere, in the machine-readable table of Table 1 and in Table 2, the row corresponding to pulsar J0952-0607 should be excised as well. Finally, in the caption for Table 2 the number of pulsars changes from "188" to "187.

GWTC-1: A Gravitational-Wave Transient Catalog of Compact Binary Mergers Observed by LIGO and Virgo during the First and Second Observing Runs

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1  M⊙ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, four of which we report here for the first time: GW170729, GW170809, GW170818, and GW170823. For all significant gravitational-wave events, we provide estimates of the source properties. The detected binary black holes have total masses between 18.6−0.7+3.2  M⊙ and 84.4−11.1+15.8  M⊙ and range in distance between 320−110+120 and 2840−1360+1400  Mpc. No neutron star-black hole mergers were detected. In addition to highly significant gravitational-wave events, we also provide a list of marginal event candidates with an estimated false-alarm rate less than 1 per 30 days. From these results over the first two observing runs, which include approximately one gravitational-wave detection per 15 days of data searched, we infer merger rates at the 90% confidence intervals of 110−3840  Gpc−3 y−1 for binary neutron stars and 9.7−101  Gpc−3 y−1 for binary black holes assuming fixed population distributions and determine a neutron star-black hole merger rate 90% upper limit of 610  Gpc−3 y−1

Searches for gravitational waves from known pulsars at two harmonics in 2015-2017 LIGO data

International audienceWe present a search for gravitational waves from 222 pulsars with rotation frequencies ≳10 Hz. We use advanced LIGO data from its first and second observing runs spanning 2015–2017, which provides the highest-sensitivity gravitational-wave data so far obtained. In this search we target emission from both the l = m = 2 mass quadrupole mode, with a frequency at twice that of the pulsar’s rotation, and the l = 2, m = 1 mode, with a frequency at the pulsar rotation frequency. The search finds no evidence for gravitational-wave emission from any pulsar at either frequency. For the l = m = 2 mode search, we provide updated upper limits on the gravitational-wave amplitude, mass quadrupole moment, and fiducial ellipticity for 167 pulsars, and the first such limits for a further 55. For 20 young pulsars these results give limits that are below those inferred from the pulsars’ spin-down. For the Crab and Vela pulsars our results constrain gravitational-wave emission to account for less than 0.017% and 0.18% of the spin-down luminosity, respectively. For the recycled millisecond pulsar J0711−6830 our limits are only a factor of 1.3 above the spin-down limit, assuming the canonical value of 1038 kg m2 for the star’s moment of inertia, and imply a gravitational-wave-derived upper limit on the star’s ellipticity of 1.2 × 10−8. We also place new limits on the emission amplitude at the rotation frequency of the pulsars

GW190425 : observation of a compact binary coalescence with total mass ~ 3.4 M o

On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were used for subsequent parameter estimation. The 90% credible intervals for the component masses range from to if we restrict the dimensionless component spin magnitudes to be smaller than 0.05). These mass parameters are consistent with the individual binary components being neutron stars. However, both the source-frame chirp mass and the total mass of this system are significantly larger than those of any other known binary neutron star (BNS) system. The possibility that one or both binary components of the system are black holes cannot be ruled out from gravitational-wave data. We discuss possible origins of the system based on its inconsistency with the known Galactic BNS population. Under the assumption that the signal was produced by a BNS coalescence, the local rate of neutron star mergers is updated to 250-2810