Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-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 amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst 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 non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences 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 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 were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital 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 an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

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

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 time scale of DM

Hasora mavis Evans, 1934 syn. n. is confirmed to be the female of H. leucospila leucospila (Mabille, 1891) (Hesperiidae, Coeliadinae) by DNA barcoding

Xue, Guoxi, Ikari, Etsuo, Inayoshi, Yutaka, Li, Meng (2019): Hasora mavis Evans, 1934 syn. n. is confirmed to be the female of H. leucospila leucospila (Mabille, 1891) (Hesperiidae, Coeliadinae) by DNA barcoding. Zootaxa 4695 (4): 391-393, DOI: https://doi.org/10.11646/zootaxa.4695.4.

A new subspecies and a new synonym of the genus Coladenia (Hesperiidae, Pyrginae) from China

The second subspecies of Coladenia buchananii (de Nicéville, 1889), viz. Coladenia buchananii separafasciata Xue, Inayoshi & Hu, ssp. n., is discovered from south Jiangxi Province and west Fujian Province, southeast China. External and genital characters of both male and female of this new subspecies are illustrated and described. Coladenia neomaeniata Fan & Wang, 2006, syn. n. is proposed to be a junior synonym of C. maeniata Oberthür, 1896, and the distribution of this species is briefly discussed

New records of Celaenorrhinus pyrrha de Nicéville, 1889 and C. munda (Moore, 1884) from China (Lepidoptera, Hesperiidae)

Celaenorrhinus pyrrha de Nicéville, 1889, a rare species of Hesperiidae previously known to be distributed from northeastern India to Indochina, is reported from southwestern Yunnan and southwestern Chongqing, China. A 658 bp COI gene sequence of this species is published for the first time. Although Chongqing is obviously isolated from the main distribution range, morphological characters of the specimens from this locality do not indicate a subspecies differentiation. Another rare taxon, C. munda munda (Moore, 1884), is also recorded from China for the first time based upon a male specimen from Cuona County in the Tibet Autonomous Region. This is the second specimen of C. munda from China, over 100 years after the holotype of C. munda joka Evans, 1949. The genitalia of both species are illustrated and described. Some taxonomic notes and a distribution map are provided as well

Graphium septentrionicolus Page & Treadaway, 2013 (Lepidoptera: Papilionidae) is a distinct species

Cotton, Adam M., Doleck, Tenzing, Zhang, Xin, Inayoshi, Yutaka, Lohman, David J., Hu, Shao-Ji (2022): Graphium septentrionicolus Page & Treadaway, 2013 (Lepidoptera: Papilionidae) is a distinct species. Zootaxa 5154 (2): 211-224, DOI: https://doi.org/10.11646/zootaxa.5154.2.