bluuebunny/crossref_metadata_2025_split huggingface dataset:
The OH Megamaser galaxy IRAS11506−3851: an AGN and star formation revealed by multiwavelength observations
Authors: Hekatelyne C , Riffel Rogemar A , Storchi-Bergmann Thaisa , Kharb Preeti , Robinson Andrew , Sales Dinalva , Cassanta Claudia M 
Published: August 2020

ABSTRACT
We present Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (IFU), Hubble Space Telescope (HST), and Very Large Array (VLA) observations of the OH Megamaser (OHM) galaxy IRAS 11506−3851. The HST images reveal an isolated spiral galaxy and the combination with the GMOS-IFU flux distributions and VLA data allow us to identify a partial ring of star-forming regions surrounding the nucleus with a radius of ≈ 500 pc. While this ring shows starburst excitation and low velocity dispersion, the region internal to the ring shows higher excitation and velocity dispersion values, with values increasing towards its borders at ≈ 240 pc from the nucleus, resembling a projected bubble. The enhanced excitation and velocity dispersion of this bubble surrounds a 8.5-GHz radio emission structure, supporting its origin in a faint active galactic nucleus (AGN) that is mostly shocking the surrounding gas via a plasma ejection seen in radio at the present stage. This is the fourth of the 5 OHM galaxies we have studied so far (from our sample of 15 OHM) for which GMOS-IFU data indicate the presence of a previously unknown faint AGN at the nucleus, consistent with the hypothesis that OHM galaxies harbour recently triggered AGN.
The SEDIGISM survey: molecular clouds in the inner Galaxy
Authors: Duarte-Cabral A , Colombo D , Urquhart J S , Ginsburg A , Russeil D , Schuller F , Anderson L D , Barnes P J , Beltrán M T , Beuther H , Bontemps S , Bronfman L , Csengeri T , Dobbs C L , Eden D , Giannetti A , Kauffmann J , Mattern M , Medina S-N X , Menten K M , Lee M-Y , Pettitt A R , Riener M , Rigby A J , Traficante A , Veena V S , Wienen M , Wyrowski F , Agurto C , Azagra F , Cesaroni R , Finger R , Gonzalez E , Henning T , Hernandez A K , Kainulainen J , Leurini S , Lopez S , Mac-Auliffe F , Mazumdar P , Molinari S , Motte F , Muller E , Nguyen-Luong Q , Parra R , Perez-Beaupuits J-P , Montenegro-Montes F M , Moore T J T , Ragan S E , Sánchez-Monge A , Sanna A , Schilke P , Schisano E , Schneider N , Suri S , Testi L , Torstensson K , Venegas P , Wang K , Zavagno A 
Published: August 2020

ABSTRACT
We use the 13CO (2–1) emission from the SEDIGISM (Structure, Excitation, and Dynamics of the Inner Galactic InterStellar Medium) high-resolution spectral-line survey of the inner Galaxy, to extract the molecular cloud population with a large dynamic range in spatial scales, using the Spectral Clustering for Interstellar Molecular Emission Segmentation (scimes) algorithm. This work compiles a cloud catalogue with a total of 10 663 molecular clouds, 10 300 of which we were able to assign distances and compute physical properties. We study some of the global properties of clouds using a science sample, consisting of 6664 well-resolved sources and for which the distance estimates are reliable. In particular, we compare the scaling relations retrieved from SEDIGISM to those of other surveys, and we explore the properties of clouds with and without high-mass star formation. Our results suggest that there is no single global property of a cloud that determines its ability to form massive stars, although we find combined trends of increasing mass, size, surface density, and velocity dispersion for the sub-sample of clouds with ongoing high-mass star formation. We then isolate the most extreme clouds in the SEDIGISM sample (i.e. clouds in the tails of the distributions) to look at their overall Galactic distribution, in search for hints of environmental effects. We find that, for most properties, the Galactic distribution of the most extreme clouds is only marginally different to that of the global cloud population. The Galactic distribution of the largest clouds, the turbulent clouds and the high-mass star-forming clouds are those that deviate most significantly from the global cloud population. We also find that the least dynamically active clouds (with low velocity dispersion or low virial parameter) are situated further afield, mostly in the least populated areas. However, we suspect that part of these trends may be affected by some observational biases (such as completeness and survey limitations), and thus require further follow up work in order to be confirmed.
Tidal forces from the wake of dynamical friction: warps, lopsidedness, and kinematic misalignment
Authors: Kipper Rain , Benito María , Tenjes Peeter , Tempel Elmo , de Propris Roberto 
Published: August 2020

ABSTRACT
A galaxy moving through a background of dark matter particles induces an overdensity of these particles or a wake behind it. The back reaction of this wake on the galaxy is a force field that can be decomposed into an effective deceleration (called dynamical friction) and a tidal field. In this paper, we determine the tidal forces, thus generated on the galaxy, and the resulting observables, which are shown to be warps, lopsidedness, and/or kinematic-photometric position angle misalignments. We estimate the magnitude of the tidal-like effects needed to reproduce the observed warp and lopsidedness on the isolated galaxy IC 2487. Within a realistic range of dark matter distribution properties, the observed, warped, and lopsided kinematical properties of IC 2487 are possible to reproduce (the background medium of dark matter particles has a velocity dispersion of $\lesssim 80\, {\rm km\, s^{-1}}$ and the density $10^4{\!-\!}10^5\, {\rm M_\odot \, kpc^{-3}}$, more likely at the lower end). We conclude that the proposed mechanism can generate warps, lopsidedness, and misalignments observed in isolated galaxies or galaxies in loose groups. The method can be used also to constrain dark matter spatial and velocity distribution properties.
Modelling the atmosphere of lava planet K2-141b: implications for low- and high-resolution spectroscopy
Authors: Nguyen T Giang , Cowan Nicolas B , Banerjee Agnibha , Moores John E 
Published: August 2020

ABSTRACT
Transit searches have uncovered Earth-size planets orbiting so close to their host star that their surface should be molten, so-called lava planets. We present idealized simulations of the atmosphere of lava planet K2-141b and calculate the return flow of material via circulation in the magma ocean. We then compare how pure Na, SiO, or SiO2 atmospheres would impact future observations. The more volatile Na atmosphere is thickest followed by SiO and SiO2, as expected. Despite its low vapour pressure, we find that a SiO2 atmosphere is easier to observe via transit spectroscopy due to its greater scale height near the day–night terminator and the planetary radial velocity and acceleration are very high, facilitating high dispersion spectroscopy. The special geometry that arises from very small orbits allows for a wide range of limb observations for K2-141b. After determining the magma ocean depth, we infer that the ocean circulation required for SiO steady-state flow is only 10−4 m s−1, while the equivalent return flow for Na is several orders of magnitude greater. This suggests that a steady-state Na atmosphere cannot be sustained and that the surface will evolve over time.
A new calibration method of sub-halo orbital evolution for semi-analytic models
Authors: Yang Shengqi , Du Xiaolong , Benson Andrew J , Pullen Anthony R , Peter Annika H G 
Published: August 2020

ABSTRACT
Understanding the non-linear dynamics of satellite haloes (a.k.a. ‘sub-haloes’) is important for predicting the abundance and distribution of dark matter sub-structures and satellite galaxies, and for distinguishing among microphysical dark matter models using observations. Typically, modelling these dynamics requires large N-body simulations with high resolution. Semi-analytic models can provide a more efficient way to describe the key physical processes such as dynamical friction, tidal mass loss, and tidal heating, with only a few free parameters. In this work, we present a fast Markov chain Monte Carlo fitting approach to explore the parameter space of such a sub-halo non-linear evolution model. We use the dynamical models described in an earlier work and calibrate the models to two sets of high-resolution cold dark matter N-body simulations, ELVIS and Caterpillar. Compared to previous calibrations that used manual parameter tuning, our approach provides a more robust way to determine the best-fitting parameters and their posterior probabilities. We find that jointly fitting for the sub-halo mass and maximum velocity functions can break the degeneracy between tidal stripping and tidal heating parameters, as well as providing better constraints on the strength of dynamical friction. We show that our semi-analytic simulation can accurately reproduce N-body simulations statistics, and that the calibration results for the two sets of N-body simulations agree at 95 per cent confidence level. Dynamical models calibrated in this work will be important for future dark matter sub-structure studies.
X-ray photolysis of CH3COCH3 ice: implications for the radiation effects of compact objects towards astrophysical ices
Authors: Carvalho G A , Pilling S 
Published: August 2020

ABSTRACT
In this study, we employed broad-band X-rays (6–2000 eV) to irradiate the frozen acetone CH3COCH3, at the temperature of 12 K, with different photon fluences up to 2.7 × 1018 photons cm−2. Here, we consider acetone as a representative complex organic molecule (COM) present on interstellar ice grains. The experiments were conduced at the Brazilian Synchrotron facility (LNLS/CNPEN) employing infrared spectroscopy (FTIR) to monitor chemical changes induced by radiation in the ice sample. We determined the effective destruction cross-section of the acetone molecule and the effective formation cross-section for daughter species. Chemical equilibrium, obtained for fluence 2 × 1018 photons cm−2, and molecular abundances at this stage were determined, which also includes the estimates for the abundance of unknown molecules, produced but not detected, in the ice. Time-scales for ices, at hypothetical snow line distances, to reach chemical equilibrium around several compact and main-sequence X-ray sources are given. We estimate time-scales of 18 d, 3.6 and 1.8 months, 1.4 × 109–6 × 1011 yr, 600 and 1.2 × 107 yr, and 107 yr, for the Sun at 5 au, for O/B stars at 5 au, for white dwarfs at 1 LY, for the Crab pulsar at 2.25 LY, for Vela pulsar at 2.25 LY, and for Sagittarius A* at 3 LY, respectively. This study improves our current understanding about radiation effects on the chemistry of frozen material, in particular, focusing for the first time, the effects of X-rays produced by compact objects in their eventual surrounding ices.
The TOI-763 system: sub-Neptunes orbiting a Sun-like star
Authors: Fridlund M , Livingston J , Gandolfi D , Persson C M , Lam K W F , Stassun K G , Hellier C , Korth J , Hatzes A P , Malavolta L , Luque R , Redfield S , Guenther E W , Albrecht S , Barragan O , Benatti S , Bouma L , Cabrera J , Cochran W D , Csizmadia S , Dai F , Deeg H J , Esposito M , Georgieva I , Grziwa S , González Cuesta L , Hirano T , Jenkins J M , Kabath P , Knudstrup E , Latham D W , Mathur S , Mullally S E , Narita N , Nowak G , Olofsson A O H , Palle E , Pätzold M , Pompei E , Rauer H , Ricker G , Rodler F , Seager S , Serrano L M , Smith A M S , Spina L , Subjak J , Tenenbaum P , Ting E B , Vanderburg A , Vanderspek R , Van Eylen V , Villanueva S , Winn J N 
Published: August 2020

ABSTRACT
We report the discovery of a planetary system orbiting TOI-763(aka CD-39 7945), a V = 10.2, high proper motion G-type dwarf star that was photometrically monitored by the TESS space mission in Sector 10. We obtain and model the stellar spectrum and find an object slightly smaller than the Sun, and somewhat older, but with a similar metallicity. Two planet candidates were found in the light curve to be transiting the star. Combining TESS transit photometry with HARPS high-precision radial velocity (RV) follow-up measurements confirm the planetary nature of these transit signals. We determine masses, radii, and bulk densities of these two planets. A third planet candidate was discovered serendipitously in the RV data. The inner transiting planet, TOI-763 b, has an orbital period of Pb  =  5.6 d, a mass of Mb  =  9.8 ± 0.8 M⊕, and a radius of Rb  =  2.37 ± 0.10 R⊕. The second transiting planet, TOI-763 c, has an orbital period of Pc  =  12.3 d, a mass of Mc  =  9.3 ± 1.0 M⊕, and a radius of Rc  =  2.87 ± 0.11 R⊕. We find the outermost planet candidate to orbit the star with a period of ∼48 d. If confirmed as a planet, it would have a minimum mass of Md  =  9.5 ± 1.6 M⊕. We investigated the TESS light curve in order to search for a mono transit by planet d without success. We discuss the importance and implications of this planetary system in terms of the geometrical arrangements of planets orbiting G-type stars.
Strengthening the bounds on the r-mode amplitude with X-ray observations of millisecond pulsars
Authors: Boztepe Tuğba , Göğüş Ersin , Güver Tolga , Schwenzer Kai 
Published: August 2020

ABSTRACT
R-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the properties of such oscillations, if their surface temperatures can be inferred. We present the results of our investigations of archival X-ray data of a number of MSPs, as well as recent XMM–Newton observations of PSR J1810+1744 and PSR J2241−5236. Using the neutron star atmosphere model and taking into account various uncertainties, we present new bounds on the surface temperature of these sources. Thereby, we significantly strengthen previous bounds on the amplitude of the r-mode oscillations in MSPs and find rigorous values as low as α ≲ 3 × 10−9. This is by now about three orders of magnitude below what standard saturation mechanisms in neutron stars could provide, which requires very strong dissipation in the interior, strongly pointing towards a structurally complex or exotic composition of these sources. At such low temperatures, sources could even be outside of the instability region, and taking into account the various uncertainties, we obtain for an observed surface temperature a simple frequency bound below which r-modes are excluded in slower spinning pulsars.
Identifying the radiative components responsible for quasi-periodic oscillations of black hole systems
Authors: Garg Akash , Misra Ranjeev , Sen Somasri 
Published: August 2020

ABSTRACT
While the dynamical origin of the variability observed in Galactic black hole systems, such as quasi-periodic oscillations (QPOs), is still a matter of debate, insight into the radiative components responsible for such behaviour can be obtained by studying their energy-dependent temporal behaviour. In particular, one needs to ascertain which variations of the parameters of the best-fitting time-averaged spectral components reproduce the observed energy-dependent fractional rms and time-lags. However, to obtain meaningful interpretation, the standard spectral component parameters have to be recast to physically relevant ones. Then, the energy-dependent temporal variations that their fluctuations will cause, needs to be predicted and compared with observations. In this work, we describe a generic method to do this and apply the technique to the ∼3–4 Hz QPOs observed in the black hole system GRS 1915+105 as observed by AstroSat where the time-averaged spectra can be represented by emission from a truncated disc and hot thermal Comptonizing coronae in the inner regions. We find that the QPOs and their harmonic can be explained in terms of correlated local accretion rate variations in the disc, the truncated disc radius, the optical depth and the heating rate of the coronae with time-delays between them. We highlight the potential of such techniques to unravel the radiative process responsible for variability using high-quality spectral and temporal data from AstroSat and NICER.
A recent major merger tale for the closest giant elliptical galaxy Centaurus A
Authors: Wang Jianling , Hammer Francois , Rejkuba Marina , Crnojević Denija , Yang Yanbin 
Published: August 2020

ABSTRACT
We have used hydrodynamical simulations to model the formation of the closest giant elliptical galaxy Centaurus A. We find that a single major merger event with a mass ratio of up to 1.5, and which has happened ∼2 Gyr ago, is able to reproduce many of its properties, including galaxy kinematics, the inner gas disc, stellar halo ages and metallicities, and numerous faint features observed in the halo. The elongated halo shape is mostly made of progenitor residuals deposited by the merger, which also contribute to stellar shells observed in the Centaurus A halo. The current model also reproduces the measured planetary nebula line-of-sight velocity and their velocity dispersion. Models with a small mass ratio and relatively low gas fraction result in a de Vaucouleurs profile distribution, which is consistent with observations and model expectations. A recent merger left imprints in the age distribution that are consistent with the young stellar and globular cluster populations (2–4 Gyr) found within the halo. We conclude that even if not all properties of Centaurus A have been accurately reproduced, a recent major merger has likely occurred to form the Centaurus A galaxy as we observe it at present day.
Evidence for a Causal Relationship Between Academic Achievement and Cigarette Smoking
Authors: Kendler Kenneth S , Ohlsson Henrik , Fagan Abigail A , Lichtenstein Paul , Sundquist Jan , Sundquist Kristina 
Published: August 2020

Abstract

Introduction
Academic achievement (AA) is associated with smoking rates. Can we determine the degree to which this relationship is likely a causal one?

Methods
We predict smoking in male conscripts (mean age 18.2) assessed from 1984 to 1991 (N = 233 248) and pregnant females (mean age 27.7) receiving prenatal care 1972–1990 (N = 494 995) from AA assessed in all students at 16. Instrumental variable (IV) analyses used the instrument month-of-birth as in each school year, older children have high AA. Co-relative analyses used AA-smoking associations in the population, cousins and siblings to predict the AA-smoking relationship in MZ twins, thereby controlling for familial confounding.

Results
In males, higher AA was associated with a substantial decrease in risk for smoking (odds ratio [OR] [95% confidence intervals [CIs]] per standard deviation [SD] = 0.41 [0.40–0.41]) while the parallel figures obtain from our IV and co-relative analyses were 0.47 (0.39–0.57) and 0.51 (0.43–0.60), respectively. In females, these figures for pre-pregnancy smoking were, respectively, 0.39 (0.39–0.39), 0.50 (0.46–0.54) and 0.54 (0.51–0.58). Results for heavy versus light smoking suggested a causal effect but were inconsistent across methods. However, among females smoking prior to pregnancy, AA predicted a reduced risk for continued smoking with ORs for uncontrolled, IV, and co-relative analyses equaling, respectively, were 0.54 (0.53–0.55) 0.68 (0.56–0.82) and 0.78 (0.66–0.91), respectively.

Conclusions
Two different methods produced consistent evidence that higher AA has a causal effect on reducing smoking rates and increasing cessation rates in smoking pregnant females. Improving AA may result in meaningful gains in population health through reduced smoking.

Implications
This study provides consistent evidence across two different methods that high AA is causally related to reduced rates of smoking and increasing rates of smoking cessation among pregnant women. Our results suggest that interventions that improve educational achievement in adolescence would reduce tobacco consumption, thereby improving public health.
Repeated Injections of Low-Dose Nerve Growth Factor (NGF) in Healthy Humans Maintain Muscle Pain and Facilitate Ischemic Contraction–Evoked Pain
Authors: Sørensen Line Bay , Gazerani Parisa , Sluka Kathleen A , Graven-Nielsen Thomas 
Published: August 2020

Abstract

Objective
Nerve growth factor (NGF) is essential for generating and potentiating pain responses. This double-blinded crossover study assessed NGF-evoked pain in healthy humans after repeated NGF injections in the tibialis anterior (TA) muscle compared with control injections of isotonic saline.

Subjects
Twenty healthy subjects participated in two experimental phases; each consisted of seven sessions over 21 days.

Methods
At day 0, day 2, and day 4, a low-dose NGF (1 µg) was injected. Data on daily self-reported muscle pain (using a Likert scale) were collected. Data on pressure pain thresholds (PPTs), pain evoked by nonischemic and ischemic muscle contractions (using a numerical rating scale [NRS]), pressure pain detection (PDT), and pain tolerance thresholds (PTTs) to cuff algometry were recorded before day 0 and at 1, 2, 4, 7, 10, and 21 days after the first injection. Temporal summation of pain (TSP) and conditioned pain modulation (CPM) were recorded to assess central pain mechanisms.

Results
Likert scores remained elevated for 9 days after NGF injection (P&lt;0.05). PPTs at the TA muscle were decreased at day 1 until day 7 after NGF injection compared with day 0 (P=0.05). In subjects presenting with NGF-induced muscle hyperalgesia, pain NRS scores evoked by nonischemic contractions were higher after NGF injection at day 4 and day 7 (P&lt;0.04) compared with the control condition. At all time points, higher pain NRS scores were found with ischemic compared with nonischemic contractions (P&lt;0.05). The pain NRS after ischemic contractions was elevated following prolonged NGF hyperalgesia at day 7 compared with the control condition and day 0 (P&lt;0.04). The PDT, PTT, TSP, and CPM remained unchanged during the period of NGF-induced hyperalgesia.

Conclusions
Repeated low-dose NGF injections maintain muscle pain and potentiate pain evoked by ischemic contractions during prolonged NGF hyperalgesia.
Interactions between Individuals on the Autism Spectrum and the Police: The Fears of Parents, Caregivers, and Professionals
Authors: Wallace Danielle , Herbert Jessica , Tyler David , McGee-Hassrick Elizabeth 
Published: August 2020

Abstract
Using data from a survey of parents, guardians, caregivers, and professionals, we couple qualitative coding with descriptive statistics to show how common it is for respondents to fear future police contact for the individual with autism spectrum disorder (ASD) in the respondents’ lives and what inspires that fear. Nearly, 60% of respondents were reported being fearful of future police contact. Respondents characterized their fear in the following ways: the potential for police officers to misunderstand behaviours common amongst individuals with ASD generally and see those behaviours as non-compliance, ineffective, or difficult communication with minimally individuals with ASD and the emergence of aggressive behaviours from individuals with ASD during police contact. Respondents also expressed concern about the potential for police misuse of force. We conclude by discussing the ramifications of fear of police contact for police training as well as parents, caregivers, and individuals with ASD.