In this work, the results of a detailed sound monitoring conducted during December 2023 in the mountain rainforest of Yungas (750 meters above sea level), in the vicinity of Piedras stream within the ...protected area of Sierra San Javier Park, are presented. The spectrograms obtained from the inner forest differ consistently from those of the riparian forest, distinguishable by their bioacoustic characteristics. It is conjectured that the stream, through its geophonic load and ecological imprint on the landscape, imposes restrictions on the occupation of the ecoacoustic niche by the fauna ensemble present in the area.
AIMS: To understand and model the dynamics of litter decomposition in a climatically seasonal region subject to different modalities of land pasture management. METHODS: Decomposition was quantified ...through the litterbag technique. Sampling was performed at monthly intervals on an annual basis with replications for 2008, 2009 and 2010. Treatments were native vegetation (NV) and grazed (G), grazed and N-fertilized (GF), hayed (H), hayed and N-fertilized (HF) plots. For each combination of treatment and year, a sigmoid model was fitted. Parameters included remnant litter, steepness and inflection of decomposition curve. RESULTS: The sigmoid model adjusted excellently well the data. In considering the overall effect on litter decomposition, treatments differ among them as follows symbolically: ((GF > G) > (HF > H)) > > NV. Results are consistent across the yearly replications. CONCLUSION: Pasture management (grazed versus hayed) is the primary factor controlling the rate of decomposition, whereas fertilization has a secondary role. The sigmoid model captures realistically the different phases of decomposition detected over a year, namely stationary at conditions of low temperature (later autumn and winter), accelerated at increasing temperature and humidity (transition from spring to summer) and decelerated when residual organic matter becomes less profitable and weather conditions more stringent (summer and earlier autumn).
A billion years ago, two black holes spiraled together, forming a new black hole. They produced gravitational waves that reached Earth on September 14, 2015, where they were measured during the first ...observing run of the Advanced LIGO detectors. This signal marked the birth of gravitational-wave astronomy, which provides a unique way to study black holes and neutron stars. The Advanced LIGO and Advanced Virgo detectors have now completed their third observing run, the latest in a series of runs, each more sensitive (and with higher detection rates) than the last. Here, we present the third Gravitational-Wave Transient Catalog (GWTC-3), which describes discoveries made up to the end of the third run.GWTC-3 contains 90 gravitational-wave candidates—35 more than the previous catalog—with better-than-even odds of being real signals. The catalog is an unprecedented census of merging black holes and neutron stars. We now have observations of binary neutron stars, binary black holes, and neutron star–black hole binaries. These cover a diverse range of masses, from neutron stars as light as 1.2 solar masses to remnant black holes exceeding 100 solar masses, and include ambiguous objects that straddle the expected divide between neutron stars and black holes.This paper details the latest results from the third observing run, from detector status and data-quality checks, to searches for signals and source-property inferences. GWTC-3 observations and associated data enable studies of compact astrophysical objects, the nature of gravity, and the history of the Universe. However, many puzzles and open questions remain to be addressed by future observing runs, which promise to yield hundreds more binary detections and possibly entirely new types of gravitational-wave sources.
We report on the population properties of 76 compact binary mergers detected with gravitational waves below a false alarm rate of 1 per year through GWTC-3. The catalog contains three classes of ...binary mergers: BBH, BNS, and NSBH mergers. We infer the BNS merger rate to be between 10 $\rm{Gpc^{-3} yr^{-1}}$ and 1700 $\rm{Gpc^{-3} yr^{-1}}$ and the NSBH merger rate to be between 7.8 $\rm{Gpc^{-3}\, yr^{-1}}$ and 140 $\rm{Gpc^{-3} yr^{-1}}$ , assuming a constant rate density versus comoving volume and taking the union of 90% credible intervals for methods used in this work. Accounting for the BBH merger rate to evolve with redshift, we find the BBH merger rate to be between 17.9 $\rm{Gpc^{-3}\, yr^{-1}}$ and 44 $\rm{Gpc^{-3}\, yr^{-1}}$ at a fiducial redshift (z=0.2). We obtain a broad neutron star mass distribution extending from $1.2^{+0.1}_{-0.2} M_\odot$ to $2.0^{+0.3}_{-0.3} M_\odot$. We can confidently identify a rapid decrease in merger rate versus component mass between neutron star-like masses and black-hole-like masses, but there is no evidence that the merger rate increases again before 10 $M_\odot$. We also find the BBH mass distribution has localized over- and under-densities relative to a power law distribution. While we continue to find the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above $\sim 60 M_\odot$. The rate of BBH mergers is observed to increase with redshift at a rate proportional to $(1+z)^{\kappa}$ with $\kappa = 2.9^{+1.7}_{-1.8}$ for $z\lesssim 1$. Observed black hole spins are small, with half of spin magnitudes below $\chi_i \simeq 0.25$. We observe evidence of negative aligned spins in the population, and an increase in spin magnitude for systems with more unequal mass ratio.
Abstract
The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during ...their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at
https://gwosc.org
. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.
The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15∶00 UTC and 1 ...October 2019 15∶00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have a probability of astrophysical origin greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. We also calculate updated source properties for all binary black hole events previously reported in GWTC-1. If the eight additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects ≥3M⊙) is increased compared to GWTC-2, with total masses from ∼14M⊙ for GW190924_021846 to ∼182M⊙ for GW190426_190642. Source properties calculated using our default prior suggest that the primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair-instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than 0.65 and 0.44 at 90% probability for GW190403_051519 and GW190917_114630 respectively), and find that two of the eight new events have effective inspiral spins χeff>0 (at 90% credibility), while no binary is consistent with χeff<0 at the same significance. We provide updated estimates for rates of binary black hole and binary neutron star coalescence in the local Universe.
Abstract We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H ( z ), ...including its current value, the Hubble constant H 0 . Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H ( z ). The source mass distribution displays a peak around 34 M ⊙ , followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H ( z ) measurement, yielding H 0 = 68 − 8 + 12 km s − 1 Mpc − 1 (68% credible interval) when combined with the H 0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H 0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+ , statistically marginalizing over the redshifts of each event’s potential hosts. Assuming a fixed BBH population, we estimate a value of H 0 = 68 − 6 + 8 km s − 1 Mpc − 1 with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H 0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H 0 ) is the well-localized event GW190814.
We present results of an all-sky search for continuous gravitational waves which can be produced by spinning neutron stars with an asymmetry around their rotation axis, using data from the third ...observing run of the Advanced LIGO and Advanced Virgo detectors. Four different analysis methods are used to search in a gravitational-wave frequency band from 10 to 2048 Hz and a first frequency derivative from $-10^{-8}$ to $10^{-9}$ Hz/s. No statistically-significant periodic gravitational-wave signal is observed by any of the four searches. As a result, upper limits on the gravitational-wave strain amplitude $h_0$ are calculated. The best upper limits are obtained in the frequency range of 100 to 200 Hz and they are ${\sim}1.1\times10^{-25}$ at 95\% confidence-level. The minimum upper limit of $1.10\times10^{-25}$ is achieved at a frequency 111.5 Hz. We also place constraints on the rates and abundances of nearby planetary- and asteroid-mass primordial black holes that could give rise to continuous gravitational-wave signals.
Abstract We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second ...observing run (O2). Searches were for emission from the l = m = 2 mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the l = 2, m = 1, 2 modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found, so we present 95% credible upper limits on the strain amplitudes h 0 for the single-harmonic search along with limits on the pulsars’ mass quadrupole moments Q 22 and ellipticities ε . Of the pulsars studied, 23 have strain amplitudes that are lower than the limits calculated from their electromagnetically measured spin-down rates. These pulsars include the millisecond pulsars J0437−4715 and J0711−6830, which have spin-down ratios of 0.87 and 0.57, respectively. For nine pulsars, their spin-down limits have been surpassed for the first time. For the Crab and Vela pulsars, our limits are factors of ∼100 and ∼20 more constraining than their spin-down limits, respectively. For the dual-harmonic searches, new limits are placed on the strain amplitudes C 21 and C 22 . For 23 pulsars, we also present limits on the emission amplitude assuming dipole radiation as predicted by Brans-Dicke theory.
