bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spaces of Gendered Jewish and Non-Jewish Encounters: Bed Lodgers, Domestic Workers, and Sex Workers in Vienna, 1900–1930*
Authors: Korbel Susanne 
Published: August 2020

Abstract
This article presents findings on encounters between Jews and non-Jews in the context of daily life in Vienna between 1900 and 1930. In the early twentieth century, the Habsburg capital underwent tremendous population growth, which increased the opportunities among its inhabitants of interreligious and cultural interactions, but also confronted them with a housing shortage. Up to twenty per cent of the population had to share housing or even beds with their fellow citizens. Those who could afford more comfortable living conditions, such as private apartments, also shared them with non-family members. The middle and upper classes employed domestics who lived with the families they worked for and had rooms within the family apartments. Homes thus provided spaces in which Jewish and non-Jewish relations thrived. This article sheds light on the range of encounters that took place in homes, how Jewishness and gender were negotiated in such encounters, whether relations were formed as a consequence, and, if so, what they looked like. Based on a close examination of memoirs, novels, and court records, I argue that the range of Jewish and non-Jewish relations was much broader than historiography has hitherto suggested, due to the shared experiences triggered by the urban making of Vienna.
Essence, Potentiality, and Modality
Authors: Vetter Barbara 
Published: August 2020

AbstractAccording to essentialism, metaphysical modality is founded in the essences of things, where the essence of a thing is roughly akin to its real definition. According to potentialism (also known as dispositionalism), metaphysical modality is founded in the potentialities of things, where a potentiality is roughly the generalized notion of a disposition. Essentialism and potentialism have much in common, but little has been written about their relation to each other. The aim of this paper is to understand better the relations between essence and potentiality, on the one hand, and between essentialism and potentialism, on the other. It is argued, first, that essence and potentiality are not duals but interestingly linked by a weaker relation dubbed ‘semi-duality’; second, that given this weaker relation, essentialism and potentialism are not natural allies but rather natural competitors; and third, that the semi-duality of essence and potentiality allows the potentialist to respond to an important explanatory challenge by using essentialist resources without thereby committing to essentialism.
A tale of two populations: surviving and destroyed dwarf galaxies and the build-up of the Milky Way’s stellar halo
Authors: Fattahi Azadeh , Deason Alis J , Frenk Carlos S , Simpson Christine M , Gómez Facundo A , Grand Robert J J , Monachesi Antonela , Marinacci Federico , Pakmor Rüdiger 
Published: August 2020

ABSTRACT
We use magnetohydrodynamical simulations of Milky Way-mass haloes from the Auriga project to investigate the properties of surviving and destroyed dwarf galaxies that are accreted by these haloes over cosmic time. We show that the combined luminosity function of surviving and destroyed dwarfs at infall is similar in the various Auriga haloes, and is dominated by the destroyed dwarfs. There is, however, a strong dependence on infall time: destroyed dwarfs typically have early infall times of less than 6 Gyr (since the big bang), whereas the majority of dwarfs accreted after 10 Gyr have survived to the present day. Because of their late infall, the surviving satellites have higher metallicities at infall than their destroyed counterparts of similar mass at infall; the difference is even more pronounced for the present-day metallicities of satellites, many of which continue to form stars after infall, in particular for $M_{\rm star}\gt 10^7 \, {\rm M}_\odot$. In agreement with previous work, we find that a small number of relatively massive destroyed dwarf galaxies dominate the mass of stellar haloes. However, there is a significant radial dependence: while 90 per cent of the mass in the inner regions (${\lt}20\,$ kpc) is contributed, on average, by only three massive progenitors, the outer regions (${\gt}100\,$ kpc) typically have ∼8 main progenitors of relatively lower mass. Finally, we show that a few massive progenitors dominate the metallicity distribution of accreted stars, even at the metal-poor end. Contrary to common assumptions in the literature, stars from dwarf galaxies of mass $M_{\rm star}\lt 10^7 \, {\rm M}_\odot$ make up less than 10 per cent of the accreted, metal poor stars ([Fe/H] ${\lt}-3$) in the inner $50\,$ kpc.
The impact of AGN wind feedback in simulations of isolated galaxies with a multiphase ISM
Authors: Torrey Paul , Hopkins Philip F , Faucher-Giguère Claude-André , Anglés-Alcázar Daniel , Quataert Eliot , Ma Xiangcheng , Feldmann Robert , Keres Dusan , Murray Norm 
Published: August 2020

ABSTRACT
Accreting black holes can drive fast and energetic nuclear winds that may be an important feedback mechanism associated with active galactic nuclei (AGN). In this paper, we implement a scheme for capturing feedback from these fast nuclear winds and examine their impact in simulations of isolated disc galaxies. Stellar feedback is modelled using the Feedback In Realistic Environments (fire) physics and produces a realistic multiphase interstellar medium (ISM). We find that AGN winds drive the formation of a low-density, high-temperature central gas cavity that is broadly consistent with analytic model expectations. The effects of AGN feedback on the host galaxy are a strong function of the wind kinetic power and momentum. Low- and moderate-luminosity AGN do not have a significant effect on their host galaxy: the AGN winds inefficiently couple to the ambient ISM and instead a significant fraction of their energy vents in the polar direction. For such massive black holes, accretion near the Eddington limit can have a dramatic impact on the host galaxy ISM: if AGN wind feedback acts for ≳20–30 Myr, the inner ∼1–10 kpc of the ISM is disrupted and the global galaxy star formation rate is significantly reduced. We quantify the properties of the resulting galaxy-scale outflows and find that the radial momentum in the outflow is boosted by a factor of ∼2–3 relative to that initially supplied in the AGN wind for strong feedback scenarios, decreasing below unity for less energetic winds. In contrast to observations, however, the outflows are primarily hot, with very little atomic or molecular gas. We conjecture that merging galaxies and high-redshift galaxies, which have more turbulent and thicker discs and very different nuclear gas geometries, may be even more disrupted by AGN winds than found in our simulations.
Spectral modification of magnetar flares by resonant cyclotron scattering
Authors: Yamasaki Shotaro , Lyubarsky Yuri , Granot Jonathan , Göğüș Ersin 
Published: August 2020

ABSTRACT
Spectral modification of energetic magnetar flares by resonant cyclotron scattering (RCS) is considered. During energetic flares, photons emitted from the magnetically trapped fireball near the stellar surface should resonantly interact with magnetospheric electrons or positrons. We show by a simple thought experiment that such scattering particles are expected to move at mildly relativistic speeds along closed magnetic field lines, which would slightly shift the incident photon energy due to the Doppler effect. We develop a toy model for the spectral distortion by a single RCS that incorporates both a realistic seed photon spectrum from the trapped fireball and the velocity field of particles, which is unique to the flaring magnetosphere. We show that our spectral model can be effectively characterized by a single parameter: the effective temperature of the fireball, which enables us to fit observed spectra with low computational cost. We demonstrate that our single-scattering model is in remarkable agreement with Swift/BAT data of intermediate flares from SGR 1900+14, corresponding to effective fireball temperatures of Teff = 6–7 keV, whereas BeppoSAX/GRBM data of giant flares from the same source may need more elaborate models including the effect of multiple scatterings. Nevertheless, since there is no standard physically motivated model for magnetar flare spectra, our model could be a useful tool to study magnetar bursts, shedding light on the hidden properties of the flaring magnetosphere.
Confirming new white dwarf-ultracool dwarf binary candidates
Authors: Hogg M A , Casewell S L , Wynn G A , Longstaff E S , Braker I P , Burleigh M R , Tilbrook R H , Geier S , Koester D , Debes J H , Lodieu N 
Published: August 2020

ABSTRACT
We present the results of a study to discover prospective new white dwarf-L dwarf binaries as identified by their near-infrared excesses in the UKIDSS catalogue. We obtained optical spectra to validate the white dwarf nature for 22 of the candidate primary stars, confirming ten as white dwarfs and determining their effective temperatures and gravities. For all 10 white dwarfs, we determined that the near-infrared excess was indeed indicative of a cool companion. Six of these are suggestive of late M dwarf companions, and three are candidate L dwarf companions, with one straddling the M−L boundary. We also present near-infrared spectra of eight additional candidate white dwarf-ultracool dwarf binaries, where the white dwarf primary had been previously confirmed. These spectra indicate one candidate at the M−L boundary, three potential L dwarf companions, and one suspected M dwarf, which showed photometric variability on a ∼6 h period, suggesting the system may be close. Radial velocity follow-up is required to confirm whether these systems are close, or widely separated.
The hydroxyl satellite-line ‘flip’ as a tracer of expanding H ii regions
Authors: Hafner Anita , Dawson J R , Wardle Mark 
Published: August 2020

ABSTRACT
Observations of the four 2Π3/2, J = 3/2 ground state transitions of the hydroxyl radical (OH) have emerged as an informative tracer of molecular gas in the Galactic interstellar medium (ISM). We discuss an OH spectral feature known as the ‘flip’, in which the satellite lines at 1612 and 1720 MHz flip – one from emission to absorption and the other the reverse – across a closely blended double feature. We highlight 30 examples of the flip from the literature, 27 of which exhibit the same orientation with respect to velocity: the 1720-MHz line is seen in emission at more negative velocities. These same examples are also observed towards bright background continuum, many (perhaps all) show stimulated emission, and 23 of these are coincident in on-sky position and velocity with H ii radio recombination lines. To explain these remarkable correlations, we propose that the 1720-MHz stimulated emission originates in heated and compressed post-shock gas expanding away from a central H ii region, which collides with cooler and more diffuse gas hosting the 1612-MHz stimulated emission. The foreground gas dominates the spectrum due to the bright central continuum; hence, the expanding post-shock gas is blue-shifted relative to the stationary pre-shock gas. We employ non-local thermodynamic equilibrium (LTE) excitation modelling to examine this scenario and find that indeed FIR emission from warm dust adjacent to the H ii region radiatively pumps the 1612-MHz line in the diffuse, cool gas ahead of the expanding shock front, while collisional pumping in the warm, dense shocked gas inverts the 1720-MHz line.
Fast radio bursts to be detected with the Square Kilometre Array
Authors: Hashimoto Tetsuya , Goto Tomotsugu , On Alvina Y L , Lu Ting-Yi , Santos Daryl Joe D , Ho Simon C-C , Wang Ting-Wen , Kim Seong Jin , Hsiao Tiger Y-Y 
Published: August 2020

ABSTRACT
Fast radio bursts (FRBs) are mysterious extragalactic radio signals. Revealing their origin is one of the central foci in modern astronomy. Previous studies suggest that occurrence rates of non-repeating and repeating FRBs could be controlled by the cosmic stellar-mass density (CSMD) and cosmic star formation-rate density (CSFRD), respectively. The Square Kilometre Array (SKA) is one of the best future instruments to address this subject due to its high sensitivity and high-angular resolution. Here, we predict the number of FRBs to be detected with the SKA. In contrast to previous predictions, we estimate the detections of non-repeating and repeating FRBs separately, based on latest observational constraints on their physical properties including the spectral indices, FRB luminosity functions, and their redshift evolutions. We consider two cases of redshift evolution of FRB luminosity functions following either the CSMD or CSFRD. At $z$ ≳ 2, $z$ ≳ 6, and $z$ ≳ 10, non-repeating FRBs will be detected with the SKA at a rate of ∼104, ∼102, and ∼10 (sky−1 d−1), respectively, if their luminosity function follows the CSMD evolution. At $z$ ≳ 1, $z$ ≳ 2, and $z$ ≳ 4, sources of repeating FRBs will be detected at a rate of ∼103, ∼102, and ≲10 (sky−1 d−1), respectively, assuming that the redshift evolution of their luminosity function is scaled with the CSFRD. These numbers could change by about one order of magnitude depending on the assumptions on the CSMD and CSFRD. In all cases, abundant FRBs will be detected by the SKA, which will further constrain the luminosity functions and number density evolutions.
Towards a non-Gaussian model of redshift space distortions
Authors: Cuesta-Lazaro Carolina , Li Baojiu , Eggemeier Alexander , Zarrouk Pauline , Baugh Carlton M , Nishimichi Takahiro , Takada Masahiro 
Published: August 2020

ABSTRACT
To understand the nature of the accelerated expansion of the Universe, we need to combine constraints on the expansion rate and growth of structure. The growth rate is usually extracted from 3D galaxy maps by exploiting the effects of peculiar motions on galaxy clustering. However, theoretical models of the probability distribution function (PDF) of galaxy pairwise peculiar velocities are not accurate enough on small scales to reduce the error on theoretical predictions to the level required to match the precision expected for measurements from future surveys. Here, we improve the modelling of the pairwise velocity distribution by using the Skew-T PDF, which has non-zero skewness and kurtosis. Our model accurately reproduces the redshift space multipoles (monopole, quadrupole, and hexadecapole) predicted by N-body simulations, above scales of about $10\, h^{-1}{\rm Mpc}$. We illustrate how a Taylor expansion of the streaming model can reveal the contributions of the different moments to the clustering multipoles, which are independent of the shape of the velocity PDF. The Taylor expansion explains why the Gaussian streaming model works well in predicting the first two redshift space multipoles, although the velocity PDF is non-Gaussian even on large scales. Indeed, any PDF with the correct first two moments would produce precise results for the monopole down to scales of about $10\, h^{-1}{\rm Mpc}$, and for the quadrupole down to about $30\, h^{-1}{\rm Mpc}$. An accurate model for the hexadecapole needs to include higher order moments.
The highly variable time evolution of star-forming cores identified with dendrograms
Authors: Smullen Rachel A , Kratter Kaitlin M , Offner Stella S R , Lee Aaron T , Chen Hope How-Huan 
Published: August 2020

ABSTRACT
We investigate the time evolution of dense cores identified in molecular cloud simulations using dendrograms, which are a common tool to identify hierarchical structure in simulations and observations of star formation. We develop an algorithm to link dendrogram structures through time using the three-dimensional density field from magnetohydrodynamical simulations, thus creating histories for all dense cores in the domain. We find that the population-wide distributions of core properties are relatively invariant in time, and quantities like the core mass function match with observations. Despite this consistency, an individual core may undergo large (&gt;40 per cent), stochastic variations due to the redefinition of the dendrogram structure between time-steps. This variation occurs independent of environment and stellar content. We identify a population of short-lived (&lt;200 kyr) overdensities masquerading as dense cores that may comprise $\sim\!20$ per cent of any time snapshot. Finally, we note the importance of considering the full history of cores when interpreting the origin of the initial mass function; we find that, especially for systems containing multiple stars, the core mass defined by a dendrogram leaf in a snapshot is typically less than the final system stellar mass. This work reinforces that there is no time-stable density contour that defines a star-forming core. The dendrogram itself can induce significant structure variation between time-steps due to small changes in the density field. Thus, one must use caution when comparing dendrograms of regions with different ages or environment properties because differences in dendrogram structure may not come solely from the physical evolution of dense cores.
Self-consistent method to extract non-linearities from pulsating star light curves – I. Combination frequencies
Authors: Lares-Martiz M , Garrido R , Pascual-Granado J 
Published: August 2020

ABSTRACT
Stellar pulsation is a common phenomenon and is sustained because of coherent driving mechanisms. When pulsations are driven by heat or convective mechanisms, it is usual to observe combination frequencies in the power spectra of the stellar light-curves. These combination frequencies are not solutions of the perturbed stellar structure equations. In dense power spectra from a light-curve of a given multiperiodic pulsating star, they can compromise the mode identification in asteroseismic analyses, and hence they must be treated as spurious frequencies and removed. In this paper, a method based on fitting the set of frequencies that best describes a general non-linear model, like the Volterra series, is presented. The method allows these frequencies to be extracted from the power spectrum, thereby improving the frequency analysis and enabling hidden frequencies to emerge from what was initially considered as noise. Moreover, the method yields frequencies with uncertainties several orders of magnitude smaller than the Rayleigh dispersion, which is sometimes used as if it were an error when identifying combination frequencies. Furthermore, it is compatible with the classical counting cycles method, the so-called O-C method, which is valid only for mono-periodic stars. The method creates the possibility of characterizing the non-linear behaviour of a given pulsating star by studying in detail the complex generalized transfer functions on which the model is based.
A broad-band X-ray spectral study of the Seyfert 1 galaxy ESO 141–G055 with XMM–Newton and NuSTAR
Authors: Ghosh Ritesh , Laha Sibasish 
Published: August 2020

ABSTRACT
We have extensively studied the broad--band X-ray spectra of the source ESO 141–G055 using all available XMM–Newton and NuSTAR observations. We detect a prominent soft excess below $2\rm \, \, {\rm keV}$, a narrow Fe line, and a Compton hump ($\gt 10\rm \, \, {\rm keV}$). The origin of the soft excess is still debated. We used two models to describe the soft excess: the blurred reflection from the ionized accretion disc and the intrinsic thermal Comptonization model. We find that both of these models explain the soft excess equally well. We confirm that we do not detect any broad Fe line in the X-ray spectra of this source, although both the physical models prefer a maximally spinning black hole scenario (a &gt; 0.96). This may mean that either the broad Fe line is absent or blurred beyond detection. The Eddington rate of the source is estimated to be $\lambda _{\rm \, Edd}\sim 0.31$. In the reflection model, the Compton hump has a contribution from both ionized and neutral reflection components. The neutral reflector which simultaneously describes the narrow Fe K α and the Compton hump has a column density of $N_{\rm H} \ge 7\times 10^{24} \, \rm cm^{-2}$. In addition, we detect a partially covering ionized absorption with ionization parameter $\log \xi /\rm \, erg\, cm\, s^{-1}$ = $0.1^{+0.1}_{-0.1}$ and column density $N_{\rm H} =20.6^{+1.0}_{-1.0}\times 10^{22} \, \rm cm^{-2}$ with a covering factor of $0.21^{+0.01}_{-0.01}$.
Validation of emission-line galaxies target selection algorithms for the Dark Energy Spectroscopic Instrument using the MMT Binospec
Authors: Karim Tanveer , Lee Jae H , Eisenstein Daniel J , Burtin Etienne , Moustakas John , Raichoor Anand , Yèche Christophe 
Published: August 2020

ABSTRACT
The forthcoming Dark Energy Spectroscopic Instrument (DESI) experiment plans to measure the effects of dark energy on the expansion of the Universe and create a 3D map of the Universe using galaxies up to z ∼ 1.6 and QSOs up to z ∼ 3.5. In order to create this map, DESI will obtain spectroscopic redshifts of over 30 million objects; among them, a majority are [O ii] emitting star-forming galaxies known as emission-line galaxies (ELGs). These ELG targets will be pre-selected by drawing a selection region on the g − r versus r − z colour–colour plot, where high-redshift ELGs form a separate locus from the lower redshift ELGs and interlopers. In this paper, we study the efficiency of three ELG target selection algorithms – the Final Design Report (FDR) cut based on the DEEP2 photometry, Number Density Modelling (NDM) and Random Forest – to determine how the combination of these three algorithms can be best used to yield a simple selection boundary that will be best suited to meet DESI’s science goals. To do this, we selected 17 small patches in the DESI footprint where we run the three target selection algorithms to pre-select ELGs based on their photometry. We observed the pre-selected ELGs using the MMT Binospec, which is similar in functionality to the DESI instrument, to obtain their spectroscopic redshifts and fluxes of 1054 ELGs. By analysing the redshift and fluxing distribution of these galaxies, we find that although NDM performed the best, simple changes in the FDR definition would also yield sufficient performance.