Abstract
We used high-precision radial velocity measurements of FGKM stars to determine the occurrence of giant planets as a function of orbital separation spanning 0.03–30 au. Giant planets are more ...prevalent at orbital distances of 1–10 au compared to orbits interior or exterior of this range. The increase in planet occurrence at ∼1 au by a factor of ∼4 is highly statistically significant. A fall-off in giant planet occurrence at larger orbital distances is favored over models with flat or increasing occurrence. We measure
14.1
−
1.8
+
2.0
giant planets per 100 stars with semimajor axes of 2–8 au and
8.9
−
2.4
+
3.0
giant planets per 100 stars in the range 8–32 au, a decrease in occurrence with increasing orbital separation that is significant at the ∼2
σ
level. We find that the occurrence rate of sub-Jovian planets (0.1–1 Jupiter masses) is also enhanced for 1–10 au orbits. This suggests that lower-mass planets may share the formation or migration mechanisms that drive the increased prevalence near the water–ice line for their Jovian counterparts. Our measurements of cold gas giant occurrence are consistent with the latest results from direct imaging surveys and gravitational lensing surveys despite different stellar samples. We corroborate previous findings that giant planet occurrence increases with stellar mass and metallicity.
Abstract
We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised exoplanets and substellar companions. This ...catalog updated the orbital parameters of known exoplanets and long-period candidates, some of which have decades-longer observational baselines than they did upon initial detection. The newly discovered exoplanets range from warm sub-Neptunes and super-Earths to cold gas giants. We present the catalog sample selection criteria, as well as over 100,000 RV measurements, which come from the Keck-HIRES, APF-Levy, and Lick-Hamilton spectrographs. We introduce the new RV search pipeline
RVSearch
(
https://california-planet-search.github.io/rvsearch/
) that we used to generate our planet catalog, and we make it available to the public as an open-source Python package. This paper is the first study in a planned series that will measure exoplanet occurrence rates and compare exoplanet populations, including studies of giant planet occurrence beyond the water ice line, and eccentricity distributions to explore giant planet formation pathways. We have made public all radial velocities and associated data that we use in this catalog.
We searched for an optical counterpart to the first gravitational-wave source discovered by LIGO (GW150914), using a combination of the Pan-STARRS1 wide-field telescope and the Public ESO ...Spectroscopic Survey of Transient Objects (PESSTO) spectroscopic follow-up programme. As the final LIGO sky maps changed during analysis, the total probability of the source being spatially coincident with our fields was finally only 4.2 per cent. Therefore, we discuss our results primarily as a demonstration of the survey capability of Pan-STARRS and spectroscopic capability of PESSTO. We mapped out 442 deg2 of the northern sky region of the initial map. We discovered 56 astrophysical transients over a period of 41 d from the discovery of the source. Of these, 19 were spectroscopically classified and a further 13 have host galaxy redshifts. All transients appear to be fairly normal supernovae (SNe) and AGN variability and none is obviously linked with GW150914. We illustrate the sensitivity of our survey by defining parametrized light curves with time-scales of 4, 20 and 40 d and use the sensitivity of the Pan-STARRS1 images to set limits on the luminosities of possible sources. The Pan-STARRS1 images reach limiting magnitudes of i
P1 = 19.2, 20.0 and 20.8, respectively, for the three time-scales. For long time-scale parametrized light curves (with full width half-maximum ≃40 d), we set upper limits of
$M_i \le -17.2^{-0.9}_{+1.4}$
if the distance to GW150914 is D
L = 400 ± 200 Mpc. The number of Type Ia SN we find in the survey is similar to that expected from the cosmic SN rate, indicating a reasonably complete efficiency in recovering SN like transients out to D
L = 400 ± 200 Mpc.
We report the discovery and multiwavelength data analysis of the peculiar optical transient, ATLAS17aeu. This transient was identified in the sky map of the LIGO gravitational wave event GW 170104 by ...our ATLAS and Pan-STARRS coverage. ATLAS17aeu was discovered 23.1 hr after GW 170104 and rapidly faded over the next three nights, with a spectrum revealing a blue featureless continuum. The transient was also detected as a fading X-ray source by Swift and in the radio at 6 and 15 GHz. The gamma-ray burst GRB 170105A was detected by three satellites 19.04 hr after GW 170104 and 4.10 hr before our first optical detection. We analyze the multiwavelength fluxes in the context of the known GRB population and discuss the observed sky rates of GRBs and their afterglows. We find it statistically likely that ATLAS17aeu is an afterglow associated with GRB 170105A, with a chance coincidence ruled out at the 99% confidence or 2.6 . A long, soft GRB within a redshift range of would be consistent with all the observed multiwavelength data. The Poisson probability of a chance occurrence of GW 170104 and ATLAS17aeu is p = 0.04. This is the probability of a chance coincidence in 2D sky location and in time. These observations indicate that ATLAS17aeu is plausibly a normal GRB afterglow at significantly higher redshift than the distance constraint for GW 170104 and therefore a chance coincidence. However, if a redshift of the faint host were to place it within the GW 170104 distance range, then physical association with GW 170104 should be considered.
Tetracationic metal phthalocyanines were synthesized by the quaternization of the
C
s
-regioisomers of tetrasubstituted zinc and magnesium phthalocyanines containing 3,5-dimethylpyrazole fragments. ...The individuality of the synthesized compounds was confirmed by HPLC‒mass spectrometry. The aggregation of the cationic metal phthalocyanines in water and aqueous-organic media, as well as in the presence of Triton X- 100 was studied. The dependence of the dimerization constant on the polarity of mixed solvents was determined.
The conditions for the energy equivalence of the effect of high-power microwave pulses and electrical video pulses on semiconductor devices are formulated and experimentally tested. The application ...of the video-pulse method is validated for the determination of parameters that characterize the hardness of micro-wave semiconductor devices against high-intensity electromagnetic interference capable of causing catastrophic failure.
Localization of the additional (doubled, tripled) infraorbital canals of the skull as well as their direction have a significant effect on the adequacy and quality of the local anaesthesia performed ...in patients, especially when performing the intracanal method of block anaesthesia. The purpose of work is to study topographic and anatomical features of doubled infraorbital canals with different forms of the skull, which affect the technique of performing by intracanal and extraoral method of infraorbital block anesthesia. Object and methods of research. We conducted anthropometric studies on 30 skulls of corpses (20 male, 10 female) aged 30-60 years. Using the caliper and ruler, the transverse (width) and anteroposterior (length) diameters of the skull were measured by the ratio which was multiplied by 100 for determining the cranial index (CI). Localization and direction of the doubled infraorbital canals were studied after injecting needles of single-use of 2-component 5 ml syringes of the Luer type (d of needles = 0.7 mm) and 3-component 1 ml insulin syringes (d of needles = 0.3-0.5 mm). Results of the research and its discussion. Doubled and tripled infraorbital canals were detected in three forms of the skull after anthropometric studies (transverse and anteroposterior diameters in 30 skulls). Doubling and tripling of the infraorbital canal was detected (in 23.33% of cases) in three skull forms, but more often it occurs in the brachycephalic form of the skull - in 13.33% of cases. Conclusions. It was found that doubling of the infraorbital canals from the right and left side of the upper jaw was found in 23.33% of cases among 20 male and 10 female skulls of different forms. In the dolichocephalic form of the skull, doubled infraorbital canals w detected in 6.66% of cases, in the brachycephalic form of the skull - in 13.33% of cases and in the mesocephalic form of the skull - in 3.33% of cases. Additional (doubled, tripled) infraorbital canals with different forms of the skull in 23.33% of cases are passable for needles (d of needles = 0.3-0.7 mm) of disposable use of 2- and 3-component syringes of the Luer type. This affects the technique of performing the intracanal method of infraorbital anesthesia. The asymmetrical direction of doubled infraorbital canals (forward, downward, inside - in 20.0% of cases and forward, downwards, outward - in 3,33% of cases) is established with respect to the main infraorbital canal. The technique of performing the intracanal method of infraorbital anesthesia depends on the number, location and direction of additional infraorbital canals.
ABSTRACT We present a search for an electromagnetic counterpart of the gravitational-wave source GW151226. Using the Pan-STARRS1 telescope we mapped out 290 square degrees in the optical iP1 filter, ...starting 11.5 hr after the LIGO information release and lasting for an additional 28 days. The first observations started 49.5 hr after the time of the GW151226 detection. We typically reached sensitivity limits of iP1 = 20.3-20.8 and covered 26.5% of the LIGO probability skymap. We supplemented this with ATLAS survey data, reaching 31% of the probability region to shallower depths of m 19. We found 49 extragalactic transients (that are not obviously active galactic nuclei), including a faint transient in a galaxy at 7 Mpc (a luminous blue variable outburst) plus a rapidly decaying M-dwarf flare. Spectral classification of 20 other transient events showed them all to be supernovae. We found an unusual transient, PS15dpn, with an explosion date temporally coincident with GW151226, that evolved into a type Ibn supernova. The redshift of the transient is secure at z = 0.1747 0.0001 and we find it unlikely to be linked, since the luminosity distance has a negligible probability of being consistent with that of GW151226. In the 290 square degrees surveyed we therefore do not find a likely counterpart. However we show that our survey strategy would be sensitive to NS-NS mergers producing kilonovae at DL 100 Mpc, which is promising for future LIGO/Virgo searches.
Herewith, we present another facet of the versatile catalytic reactivity of bulky bis-amino-bis-pyridylmethyl Mn complexes: besides highly enantioselective (up to 99% ee) epoxidation, ...benzhydryl-substituted Mn catalysts have been found to convert olefinic substrates into the products of syn-addition to the CC bond, hydroxy-carboxylates, that can prevail under certain conditions. The mechanism of syn-hydroxy-acyloxylation is discussed, with the data obtained providing evidence in favor of the so far lacking direct enantioselective OH and OC(O)R transfer from the high-valent Mn active species to the olefinic CC group. Such a mechanism is conceptually reminiscent of Rieske dioxygenases that catalyze enantioselective 1,2-dihydroxylation of CC bonds, simultaneously incorporating two cis-ligands from the reactive metal center into the resulting diol in a syn-selective fashion.
The design scheme is considered for a gas separator as used in oil extraction for the partial removal of gas from oil entering a submersed pump. Successive approximation is used in determining the ...characteristics with the use of an experimental factor
φ
, which incorporates the effects of the inlet section and flow separator on the performance. The calculated characteristics agree satisfactorily with experimental curves for high flow rates.
PDF
