Localizing merging black holes with sub-arcsecond precision using gravitational-wave lensing

The current gravitational-wave localization methods rely mainly on sources with electromagnetic counterparts. Unfortunately, a binary black hole does not emit light. Due to this, it is generally not possible to localize these objects precisely. However, strongly lensed gravitational waves, which are forecasted in this decade, could allow us to localize the binary by locating its lensed host galaxy. Identifying the correct host galaxy is challenging because there are hundreds to thousands of other lensed galaxies within the sky area spanned by the gravitational-wave observation. However, we can constrain the lensing galaxy's physical properties through both gravitational-wave and electromagnetic observations. We show that these simultaneous constraints allow one to localize quadruply lensed waves to one or at most a few galaxies with the LIGO/Virgo/Kagra network in typical scenarios. Once we identify the host, we can localize the binary to two sub-arcsec regions within the host galaxy. Moreover, we demonstrate how to use the system to measure the Hubble constant as a proof-of-principle application.Comment: 5 pages (main text) + 5 pages (methods+references), 5 figures. Accepted to MNRA

Distribution of Complex and Core Lipids within New Hyperthermophilic Members of the Archaea Domain

Core and complex lipids of several new hyperthermophilic archaeal isolates were analyzed. The organisms belong to the Sulfolobales,Archaeoglobus, Pyrobaculum, and Methanococcus. A detailed structural investigation of complex lipids of Pyrobaculum species is reported. The different lipid structures are of help for a rapid and simple phylogenetic classification of the new isolates. They are in agreement with the classification based on other features

Intermolecular interaction of photoexcited Cu(TMpy-P4) with water studied by transient resonance Raman and picosecond absorption spectroscopies

photoinduced complex between Cu(TMpy-P4) and water molecules, reversibly axially coordinated to the central metal, was observed in picosecond transient absorption and nanosecond resonance Raman experiments. This complex is rapidly created (τ1 = 15 ± 5 ps) in the excited triplet (π, π*) state of Cu-porphyrin, and the subsequent relaxation is proposed to proceed via two parallel pathways. One is fast and efficient (≥90% of molecules), and presumably involves a (π, d) charge-transfer state. The second pathway is slow (τ2 >> 1 ns), has a low quantum yield (≤10%) and involves the excited (d, d) state which is responsible for transient Raman features at ≈ 1553 cm−1 (ν2*) and ≈ 1347 cm−1 (ν4*), and for low-intensity long-lived transient absorption features

Comments on the classification of the finite subgroups of SU(3)

Many finite subgroups of SU(3) are commonly used in particle physics. The classification of the finite subgroups of SU(3) began with the work of H.F. Blichfeldt at the beginning of the 20th century. In Blichfeldt's work the two series (C) and (D) of finite subgroups of SU(3) are defined. While the group series Delta(3n^2) and Delta(6n^2) (which are subseries of (C) and (D), respectively) have been intensively studied, there is not much knowledge about the group series (C) and (D). In this work we will show that (C) and (D) have the structures (C) \cong (Z_m x Z_m') \rtimes Z_3 and (D) \cong (Z_n x Z_n') \rtimes S_3, respectively. Furthermore we will show that, while the (C)-groups can be interpreted as irreducible representations of Delta(3n^2), the (D)-groups can in general not be interpreted as irreducible representations of Delta(6n^2).Comment: 15 pages, no figures, typos corrected, clarifications and references added, proofs revise

lensingGW: a Python package for lensing of gravitational waves

Advanced LIGO and Advanced Virgo could observe the first lensed gravitational waves in the coming years, while the future Einstein Telescope could observe hundreds of lensed events. Ground-based gravitational-wave detectors can resolve arrival time differences of the order of the inverse of the observed frequencies. As LIGO/Virgo frequency band spans from a few $\rm Hz$ to a few $\rm kHz$, the typical time resolution of current interferometers is of the order of milliseconds. When microlenses are embedded in galaxies or galaxy clusters, lensing can become more prominent and result in observable time delays at LIGO/Virgo frequencies. Therefore, gravitational waves could offer an exciting alternative probe of microlensing. However, currently, only a few lensing configurations have been worked out in the context of gravitational-wave lensing. In this paper, we present lensingGW, a Python package designed to handle both strong and microlensing of compact binaries and the related gravitational-wave signals. This synergy paves the way for systematic parameter space investigations and the detection of arbitrary lens configurations and compact sources. We demonstrate the working mechanism of lensingGW and its use to study microlenses embedded in galaxies.Comment: 11 pages, 10 figure

Improving Detection of Gravitational wave Microlensing Using Repeated Signals Induced by Strong Lensing

Microlensing imprints by typical stellar mass lenses on gravitational waves are challenging to identify in the LIGO and Virgo frequency band because such effects are weak. However, stellar mass lenses are generally embedded in lens galaxies such that strong lensing accompanies microlensing. Therefore, events that are strongly lensed in addition to being microlensed may significantly improve the inference of the latter. We present a proof of principle demonstration of how one can use parameter estimation results from one strongly lensed signal to enhance the inference of the microlensing effects of the other signal with the Bayesian inference method currently used in gravitational wave astronomy. We expect this to significantly enhance our future ability to detect the weak imprints from stellar mass objects on gravitational-wave signals from colliding compact objects.Comment: 8 pages, 5 figures, presented at TAUP 202

RAT AND MOUSE BRAIN HISTAMINE N -METHYLTRANSFERASE: MODULATION BY METHYLATED INDOLEAMINES 1

A purification procedure for rat and mouse brain histamine N -methyltransferase (HMT, EC 2.1.1.8) is described which achieves the preparation of 87-fold purified rat brain and 166-fold purified mouse brain enzyme. The purified HMT (MW 29,000) is inhibited by a number of physiologically and pharmacologically active amines, among them several methylated indoleamines, at concentrations above 5 ± 10 -6 M. At concentrations below 1 ± 10 -7 M, most of the methylated indoleamines stimulate HMT , provided histamine is maintained at, or close to, its optimal concentration as an HMT substrate, namely 1 ± 10 -5 M. A study of the nature of the inhibitory process revealed a non-competitive inhibition of HMT by dopamine as against a competitive inhibition of the enzyme by most methylated indoleamines. Increasing the concentration of histamine beyond the optimal value, i.e. to inhibitory levels, resulted in less stimulation. The findings support the notion that MSO elicits the formation in selected brain cells of supranormal amounts of several methylated indoleamines which are able to stimulate HMT (and possibly other methyltransferases, see Salas et al. , 1977), thereby causing the depletion of the cerebral levels of S-adenosyl-L-methionine, reported previously (Schatz & Sellinger, 1975b).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65930/1/j.1471-4159.1978.tb06548.x.pd