J. H. Romie’s research while affiliated with Gemini North Observatory and other places

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Publications (588)


Table 2 (continued)
Figure 4. 95% credible upper limits on ellipticity ε 95% and mass quadrupole Q 95% 22
Figure 6. Blue stars show the ratio between the O4a h0 upper limits for the analyzed targets (excluding the glitching pulsars) assuming the single-harmonic model divided by the corresponding h0 upper limits in Abbott et al. (2022) for the Bayesian method as a function of the corresponding frequency at twice the rotation frequency (red circles refer instead to the C21 parameter at the rotation frequency assuming the dual-harmonic model). Blue filled stars show the h0 upper limit ratios considering the targets (J0205+6449, J0737−3039A, J1813−1246, J1831−0952, J1837−0604) analyzed using O2 (Abbott et al. 2019c) and O1 data (blue asterisk for J1826−1334, Abbott et al. (2017b)).
Table of the results for the targeted search on the set of 45 known pulsars for the three considered pipelines described in Section 3.
Search for continuous gravitational waves from known pulsars in the first part of the fourth LIGO-Virgo-KAGRA observing run
  • Preprint
  • File available

January 2025

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81 Reads

The LIGO Scientific Collaboration

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the Virgo Collaboration

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the KAGRA Collaboration

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[...]

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E. Zubieta

Continuous gravitational waves (CWs) emission from neutron stars carries information about their internal structure and equation of state, and it can provide tests of General Relativity. We present a search for CWs from a set of 45 known pulsars in the first part of the fourth LIGO--Virgo--KAGRA observing run, known as O4a. We conducted a targeted search for each pulsar using three independent analysis methods considering the single-harmonic and the dual-harmonic emission models. We find no evidence of a CW signal in O4a data for both models and set upper limits on the signal amplitude and on the ellipticity, which quantifies the asymmetry in the neutron star mass distribution. For the single-harmonic emission model, 29 targets have the upper limit on the amplitude below the theoretical spin-down limit. The lowest upper limit on the amplitude is 6.4 ⁣× ⁣10276.4\!\times\!10^{-27} for the young energetic pulsar J0537-6910, while the lowest constraint on the ellipticity is 8.8 ⁣× ⁣1098.8\!\times\!10^{-9} for the bright nearby millisecond pulsar J0437-4715. Additionally, for a subset of 16 targets we performed a narrowband search that is more robust regarding the emission model, with no evidence of a signal. We also found no evidence of non-standard polarizations as predicted by the Brans-Dicke theory.

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Figure 2. Radio energy versus luminosity distance for the SGR 1935+2154 FRBs investigated in this work (dark orange, U. Giri et al. 2023) and for 749 other public FRBs published by CHIME/FRB and others (E. Petroff et al. 2016; K. M. Rajwade et al. 2020; CHIME/FRB Collaboration et al. 2021) (blue). The FRB sample and the calculation of distances and radio energies is described in G. Principe et al. (2023) (with the exception of the FRBs studied in R. Abbott et al. 2023, for which we use the lower bound 90% distances from that analysis). Note that the radio energies from CHIME/ FRB (derived from fluxes and fluences) should be interpreted as lower limits (CHIME/FRB Collaboration et al. 2021; B. C. Andersen et al. 2023). We show the radio energy required to produce a flare as bright as that of the brighest FRB from SGR 1935+2154, FRB20200428D, as a function of distance.
Parameters for Waveforms Injected into Off-source Data for Recovery to Quantify each Search's Sensitivity
A Search Using GEO600 for Gravitational Waves Coincident with Fast Radio Bursts from SGR 1935+2154

December 2024

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57 Reads

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1 Citation

The Astrophysical Journal

The magnetar SGR 1935+2154 is the only known Galactic source of fast radio bursts (FRBs). FRBs from SGR 1935+2154 were first detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB and the Survey for Transient Astronomical Radio Emission 2 in 2020 April, after the conclusion of the LIGO, Virgo, and KAGRA Collaborations’ O3 observing run. Here, we analyze four periods of gravitational wave (GW) data from the GEO600 detector coincident with four periods of FRB activity detected by CHIME/FRB, as well as X-ray glitches and X-ray bursts detected by NICER and NuSTAR close to the time of one of the FRBs. We do not detect any significant GW emission from any of the events. Instead, using a short-duration GW search (for bursts ≤1 s) we derive 50% (90%) upper limits of 10 ⁴⁸ (10 ⁴⁹ ) erg for GWs at 300 Hz and 10 ⁴⁹ (10 ⁵⁰ ) erg at 2 kHz, and constrain the GW-to-radio energy ratio to ≤10 ¹⁴ −10 ¹⁶ . We also derive upper limits from a long-duration search for bursts with durations between 1 and 10 s. These represent the strictest upper limits on concurrent GW emission from FRBs.


Advanced LIGO detector performance in the fourth observing run

November 2024

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32 Reads

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1 Citation

On May 24th, 2023, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), joined by the Advanced Virgo and KAGRA detectors, began the fourth observing run for a two-year-long dedicated search for gravitational waves. The LIGO Hanford and Livingston detectors have achieved an unprecedented sensitivity to gravitational waves, with an angle-averaged median range to binary neutron star mergers of 152 Mpc and 160 Mpc, and duty cycles of 65.0% and 71.2%, respectively, with a coincident duty cycle of 52.6%. The maximum range achieved by the LIGO Hanford detector is 165 Mpc and the LIGO Livingston detector 177 Mpc, both achieved during the second part of the fourth observing run. For the fourth run, the quantum-limited sensitivity of the detectors was increased significantly due to the higher intracavity power from laser system upgrades and replacement of core optics, and from the addition of a 300 m filter cavity to provide the squeezed light with a frequency-dependent squeezing angle, part of the A+ upgrade program. Altogether, the A+ upgrades led to reduced detector-wide losses for the squeezed vacuum states of light which, alongside the filter cavity, enabled broadband quantum noise reduction of up to 5.2 dB at the Hanford observatory and 6.1 dB at the Livingston observatory. Improvements to sensors and actuators as well as significant controls commissioning increased low frequency sensitivity. This paper details these instrumental upgrades, analyzes the noise sources that limit detector sensitivity, and describes the commissioning challenges of the fourth observing run.


Search for gravitational waves emitted from SN 2023ixf

October 2024

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170 Reads

We present the results of a search for gravitational-wave transients associated with core-collapse supernova SN 2023ixf, which was observed in the galaxy Messier 101 via optical emission on 2023 May 19th, during the LIGO-Virgo-KAGRA 15th Engineering Run. We define a five-day on-source window during which an accompanying gravitational-wave signal may have occurred. No gravitational waves have been identified in data when at least two gravitational-wave observatories were operating, which covered 14%\sim 14\% of this five-day window. We report the search detection efficiency for various possible gravitational-wave emission models. Considering the distance to M101 (6.7 Mpc), we derive constraints on the gravitational-wave emission mechanism of core-collapse supernovae across a broad frequency spectrum, ranging from 50 Hz to 2 kHz where we assume the GW emission occurred when coincident data are available in the on-source window. Considering an ellipsoid model for a rotating proto-neutron star, our search is sensitive to gravitational-wave energy 1×105Mc21 \times 10^{-5} M_{\odot} c^2 and luminosity 4×105Mc2/s4 \times 10^{-5} M_{\odot} c^2/\text{s} for a source emitting at 50 Hz. These constraints are around an order of magnitude more stringent than those obtained so far with gravitational-wave data. The constraint on the ellipticity of the proto-neutron star that is formed is as low as 1.04, at frequencies above 1200 Hz, surpassing results from SN 2019ejj.


A search using GEO600 for gravitational waves coincident with fast radio bursts from SGR 1935+2154

October 2024

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76 Reads

The magnetar SGR 1935+2154 is the only known Galactic source of fast radio bursts (FRBs). FRBs from SGR 1935+2154 were first detected by CHIME/FRB and STARE2 in 2020 April, after the conclusion of the LIGO, Virgo, and KAGRA Collaborations' O3 observing run. Here we analyze four periods of gravitational wave (GW) data from the GEO600 detector coincident with four periods of FRB activity detected by CHIME/FRB, as well as X-ray glitches and X-ray bursts detected by NICER and NuSTAR close to the time of one of the FRBs. We do not detect any significant GW emission from any of the events. Instead, using a short-duration GW search (for bursts \leq 1 s) we derive 50\% (90\%) upper limits of 104810^{48} (104910^{49}) erg for GWs at 300 Hz and 104910^{49} (105010^{50}) erg at 2 kHz, and constrain the GW-to-radio energy ratio to 10141016\leq 10^{14} - 10^{16}. We also derive upper limits from a long-duration search for bursts with durations between 1 and 10 s. These represent the strictest upper limits on concurrent GW emission from FRBs.


Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

September 2024

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84 Reads

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11 Citations

The Astrophysical Journal

Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M ⊙ ) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≤ 0.3 at 16.9 Gpc ⁻³ yr ⁻¹ at the 90% confidence level.


Squeezing the quantum noise of a gravitational-wave detector below the standard quantum limit

September 2024

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56 Reads

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17 Citations

Science

The Heisenberg uncertainty principle dictates that the position and momentum of an object cannot be simultaneously measured with arbitrary precision, giving rise to an apparent limitation known as the standard quantum limit (SQL). Gravitational-wave detectors use photons to continuously measure the positions of freely falling mirrors and so are affected by the SQL. We investigated the performance of the Laser Interferometer Gravitational-Wave Observatory (LIGO) after the experimental realization of frequency-dependent squeezing designed to surpass the SQL. For the LIGO Livingston detector, we found that the upgrade reduces quantum noise below the SQL by a maximum of three decibels between 35 and 75 hertz while achieving a broadband sensitivity improvement, increasing the overall detector sensitivity during astrophysical observations.


LIGO Detector Characterization in the first half of the fourth Observing run

September 2024

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85 Reads

Progress in gravitational-wave astronomy depends upon having sensitive detectors with good data quality. Since the end of the LIGO-Virgo-KAGRA third Observing run in March 2020, detector-characterization efforts have lead to increased sensitivity of the detectors, swifter validation of gravitational-wave candidates and improved tools used for data-quality products. In this article, we discuss these efforts in detail and their impact on our ability to detect and study gravitational-waves. These include the multiple instrumental investigations that led to reduction in transient noise, along with the work to improve software tools used to examine the detectors data-quality. We end with a brief discussion on the role and requirements of detector characterization as the sensitivity of our detectors further improves in the future Observing runs.


Ultralight vector dark matter search using data from the KAGRA O3GK run

August 2024

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103 Reads

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8 Citations

Physical Review D

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation timescale of DM.


Search for Gravitational-lensing Signatures in the Full Third Observing Run of the LIGO–Virgo Network

July 2024

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83 Reads

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31 Citations

The Astrophysical Journal

Gravitational lensing by massive objects along the line of sight to the source causes distortions to gravitational wave (GW) signals; such distortions may reveal information about fundamental physics, cosmology, and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO-Virgo network. We search for repeated signals from strong lensing by (1) performing targeted searches for subthreshold signals, (2) calculating the degree of overlap among the intrinsic parameters and sky location of pairs of signals, (3) comparing the similarities of the spectrograms among pairs of signals, and (4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by (1) frequency-independent phase shifts in strongly lensed images, and (2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the nondetection of GW lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.


Citations (64)


... These events are most common in younger, non-recycled pulsars with rarer glitches seen in some millisecond pulsars (Cognard & Backer 2004;McKee et al. 2016). Some searches (e.g., Keitel et al. 2019;Abbott et al. 2022;Abac et al. 2024a) look for transient GWs in the aftermath of glitches. ...

Reference:

Search for continuous gravitational waves from known pulsars in the first part of the fourth LIGO-Virgo-KAGRA observing run
A Search Using GEO600 for Gravitational Waves Coincident with Fast Radio Bursts from SGR 1935+2154

The Astrophysical Journal

... The majority of observed gravitational waves originates from the mergers of stellar-mass binary black holes in the relatively local Universe. Gravitational-wave observations are not limited to the local Universe, however; the detection horizon of the Advanced LIGO and Virgo network now extends to or beyond redshift z ≈ 1 (Abbott et al. 2023a; Capote et al. 2024). In addition max.lalleman@uantwerpen.be to studying the demographics of local compact binary mergers, we therefore have an opportunity to study how these demographics systematically evolve over cosmic time. ...

Advanced LIGO detector performance in the fourth observing run

... More efficient quantum technologies can emerge through the careful choice of how information is encoded. For example, rather than increasing the photon flux in LIGO, enhancing sensitivity to optical path using squeezed states of light has led to unprecedented gravitational wave detection accuracy [1]. Conversely, qubits can become more resilient to noise if they are encoded non-locally (Fig. 1A,B) [2], as in Majorana [3] or GKP states [4]. ...

Squeezing the quantum noise of a gravitational-wave detector below the standard quantum limit
  • Citing Article
  • September 2024

Science

... On the other hand, if ULDM exists around black holes, it could have non-negligible effects, such as influencing binary black hole dynamics [16][17][18] or inducing superradiance [19,20]. These effects suggest that GWIs can also be used for indirect ULDM searches [21][22][23][24][25]. Recently, the prospects of detecting ULDM with GWIs have been widely studied [26][27][28][29][30][31][32][33][34][35][36][37][38][39], and constraints based on the observation from current GWIs have also been placed on various types of ULDM [40][41][42][43][44][45][46][47][48][49][50][51][52]. ...

Ultralight vector dark matter search using data from the KAGRA O3GK run
  • Citing Article
  • August 2024

Physical Review D

... Indeed, both the first strongly lensed binary black hole (BH) and binary neutron star (NS) mergers are expected for the beginning of the fifth LVK observation run (O5) (e.g. Abbott et al. 2021Abbott et al. , 2024. ...

Search for Gravitational-lensing Signatures in the Full Third Observing Run of the LIGO–Virgo Network

The Astrophysical Journal

... The recent observations by LIGO, Virgo, and KAGRA have established the study of gravitational waves as a central area of research in theoretical physics [2][3][4]. Dynamical binary black hole (BH) solutions can model the complex dynamics of common gravitational wave sources. Yet, constructing these solutions in General Relativity (GR) is exceptionally challenging, as the problem lacks generic symmetries and involves fundamentally time-dependent processes. ...

Observation of Gravitational Waves from the Coalescence of a 2.5–4.5 M ⊙ Compact Object and a Neutron Star

The Astrophysical Journal Letters

... Instrumental investigations carried out by the DetChar group are crucial for understanding the impact of various noise sources on detector data quality [19]. The Physical Environment and Monitoring (PEM) investigations are often carried out at the sites and require a strong co-ordination between the DetChar group and the instrument scientists at the site [20]. ...

Searching for the causes of anomalous Advanced LIGO noise
  • Citing Article
  • May 2023

... For example, the measurability of many event parameters, such as the spin parameters of a detected signal, is not proportional to f −7/3 [35]; these measurements are more strongly dependent on the low-frequency sensitivity than the inspiral range. There are also many expected sources of gravitational waves, such as the BNS post-merger [32] or magnetar bursts [36], at frequencies higher than included in the inspiral range. Many signals are not broadband, such as continuous wave sources [37]; hence, the sensitivity to these sources is already represented by the detector's sensitivity at the frequency of interest. ...

Search for Gravitational-wave Transients Associated with Magnetar Bursts in Advanced LIGO and Advanced Virgo Data from the Third Observing Run

The Astrophysical Journal

... No gravitational signal was found in association neither to Fast Radio Bursts detected by CHIME/FRB during O3a [32], nor to magnetar bursts during O3 [38]. In addition, the joint Fermi-GBM and Swift-BAT Analysis [106] and the Swift-BAT GUANO follow-up [178] of gravitational candidates during O3 run were negative. The search for coincident optical, high energy candidates in Swift observations and gravitational candidates was negative [132]. ...

A Joint Fermi-GBM and Swift-BAT Analysis of Gravitational-wave Candidates from the Third Gravitational-wave Observing Run

The Astrophysical Journal