adsabs/FOCAL huggingface dataset:
At present, few very wide binaries are known where a planetary system was discovered around one of the stellar components. The star HD 20782 is the binary companion of HD 20781, with a projected separation of ~9000 AU, and it hosts a Jupiter-mass planet on a very eccentric orbit at ~1.4 AU (Jones et al. 2006)2. The very high eccentricity reported in the literature (e = 0.97) could be the result of significant perturbations experienced by the planet during the evolution of the system and might be due to the stellar companion. In this binary system, where both the components can be well analysed separately, a comparative study of the physical properties of the pair could help explain the nature of the planetary system. To investigate any existing link between the planet formation mechanisms and the chemical composition of the host stars, Mack et al. (2014) performed a detailed elemental abundance analysis of the atmospheres of HD 20781/82, by considering that both stars host planets. This kind of study, when at least one component hosts a close-in giant planet, could result in the evidence of chemical imprints left in the parent star suggesting the ingestion of material from the circumstellar disk (and possibly also from planets) driven by the dynamical evolution of the planet orbit. When a star with a close-in giant planet is found to be enriched with elements of high condensation temperature, as suggested by Schuler et al. (2011b), this can be related to the inward migration of the planet from the outer regions of the circumstellar disk, where it formed, to the present position closer to the star (Ida & Lin 2008; Raymond et al. 2011). Mack et al. (2014) found quite significant positive trends for both stars with the condensation temperature among the elemental abundances, and suggested that the host stars accreted rocky bodies with mass between 10 and 20 M⊕ initially formed inside the location of the detected planets. Searches for abundance anomalies possibly caused by the ingestion of planetary material by the central star were also conducted by (Desidera et al. 2004, 2007; and references therein) for a sample of wide binaries. These authors found that the amount of iron accreted by the companion that is nominally richer in metal (in binaries with components having Teff> 5500 K) is comparable to the estimates of the rocky material accreted by the Sun during its main-sequence lifetime, and therefore concluded that the metal enrichment due to the ingestion of material of planetary origin is not a common event.
Citation: Mack et al. (2014)
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Citation: Mack et al. (2014)
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Citation: Jones et al. 2006
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Measurements of star-planet alignments are essential to improving our understanding of exoplanet formation and evolution, especially for planets that migrated close to their star. Disk-driven migration is expected to conserve the initial alignment between the angular momentums of the protoplanetary disk and of the planetary orbits (e.g., Winn & Fabrycky 2015). A variety of formation and migration pathways can, however, lead to misalignments between the spins of a star and of its planets’ orbits, namely: a primordial tilt of the star or the protoplanetary disk (e.g., Lai et al. 2011; Bate et al. 2010; Fielding et al. 2015); a tidal torque on the protoplanetary disk from a neighboring star (e.g., Lai 2014; Batygin 2012; Zanazzi & Lai 2018); a tidal torque on the inner planetary system from an outer companion (e.g., Huber et al. 2013); and scattering or secular interactions between the inner planets and an outer planetary or stellar companion (e.g., Wu & Murray 2003; Chatterjee et al. 2008; Fabrycky & Tremaine 2007; Teyssandier et al. 2013). In this context, determining the orbital architecture of multi-planet systems is of great relevance as the mutual inclinations between theplanets, and with the star, can help distinguish among various formation and migration scenarios. Early measurements revealed coplanar orbits that are well aligned with the stellar equator in multi-planet systems (e.g. Figueira et al. 2012; Hirano et al. 2012; Sanchis-Ojeda et al. 2012; Albrecht et al. 2013; Chaplin et al. 2013; Van Eylen et al. 2014), standing in contrast to the broad distribution of misalignments observed for hot Jupiters (e.g., Naoz et al. 2012; Albrecht et al. 2012; Davies et al. 2014) and suggesting that their orbital planes still trace a primordial alignment with the protoplanetary disk. Interestingly, spin-orbit measurements in young systems (100 Myr) have shown prograde and aligned orbits (Palle et al. 2020; Zhou et al. 2020; Mann et al. 2020). Other studies have unveiled substantial misalignments in multi-planet systems (Huber et al. 2013; Walkowicz & Basri 2013; Hirano et al. 2014; Hjorth et al. 2021; Zhang et al. 2021), hinting at more complex formation processes (e.g., Spalding & Batygin 2014; Spalding & Millholland 2020) or dynamical histories (e.g. Gratia & Fabrycky 2017).
Citation: Lai 2014
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Citation: Figueira et al. 2012
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Each 7-tile observation with Swift-XRT covers ∼ 0.8 deg2, with typical exposures of 1–2 ks per tile. In such exposure times, our detection limit is 6–10 × 10−13 erg cm−2 s−1(corresponding to 90 per cent completeness; see Evans et al. 2014, fig. 14). This is significantly more sensitive than the RASS, which covers 92 per cent of the sky down to 0.1 ct s−1 in the PSPC6 (Voges et al. 1999), which corresponds to 2.8 × 10−12 erg cm−2 s−1 in the 0.3–10 keV band covered by XRT (assuming the canonical AGN spectrum described above). For absorbed sources (i.e. with little flux in the ROSAT bandpass), the increase in sensitivity of Swift-XRT over ROSAT is even greater. The XSS provides hard-band coverage, being sensitive to ∼ 3 × 10−12 erg cm−2 s−1 in the 2–10 keV band (Warwick et al. 2012), however it only covers ∼ 2/3 of the sky. Because of the sensitivity of the XRT compared to these catalogues, and the low spatial coverage of deeper catalogues like 1CSC (Evans et al. 2010),7 3XMMi-DR4 (Watson et al., in preparation) and 1SXPS (Evans et al. 2014), we expect to discover uncatalogued X-ray sources that are serendipitously present in the IceCube error region. We therefore need to be able to identify the true X-ray counterpart to the neutrino trigger from among the unrelated objects detected in the field of view. The first step is to remove any sources which are already known X-ray emitters (and are not in outburst at the time of the Swift observations). We searched the X-ray Master catalogue8 for any catalogued X-ray object with a position agreeing with our XRT position at the 3σ level (including any systematic errors on the catalogued positions). For all observations after 2012 October9 we also searched for matches in the 1SXPS catalogue. The sources with catalogue matches are indicated in Table 2, and details of the matches are given in Table 4. In all cases where a match was found, the XRT flux was consistent with (at the 2σ level) or occasionally slightly lower than the catalogued flux, therefore these sources were all rejected as possible counterparts.
Citation: Warwick et al. 2012
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Citation: Evans et al. 2010
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While these large monitoring campaigns are important for establishing the distribution of accretion variability events, their low angular resolution precludes a detailed investigation of how the envelope structure may influence the response to accretion luminosity variations. Modeling of the envelope response predicts that higher-resolution observations may be more sensitive to accretion rate changes, as the change in brightness of the outer envelope is likely to be dominated by heating from the interstellar radiation field (ISRF; Johnstone et al. 2013). The details of the envelope structure, including the likely presence of outflow cavities and dust sublimation fronts, may also impact the observed response (Baek et al. 2020; hereafter, B20). High-resolution monitoring of embedded protostars with millimeter wavelength facilities should thus be able to probe the envelope structure, in addition to identifying variability behavior. In this paper, we thus analyze observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Submillimeter Array (SMA) of variable protostars in Serpens Main, monitored by the JCMT Transient Survey. Particular emphasis is placed on EC 53 (V371 Ser), which exhibits ∼18 month periodic accretion bursts, the most recent of which was observed at high cadence with the SMA and JCMT. We interpret the light curves from our monitoring programs using a simple toy model of the propagation of accretion bursts through the envelope, which we also use to further explore how the properties of the envelope and observational setup affect the burst response. The remainder of this paper is organized as follows. In Section 2, we describe our variable protostar targets and the ALMA, SMA, and JCMT observations, while in Section 3, we provide the details of our data reduction and present light curves of our targets. In Section 4, we develop a toy model to interpret the SMA and JCMT observations of EC 53, and this is followed in Section 5 by a further exploration with the toy model of the observation of generic accretion bursts. We then discuss our results and observational/modeling caveats in Section 6, and finish with a brief summary of our major conclusions in Section 7.
Citation: Johnstone et al. 2013
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Citation: Baek et al. 2020
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Figure 6 shows the merger rate density computed with Eq. (9) for each of the data introduced in Sect. 4.2 and for the two z >  4 ALPINE bins. For the sake of simplicity, in this case we report only the data points obtained by adopting the Kitzbichler & White (2008) prescription for the merger timescale. When using the TMM(z) redshift evolution from Jiang et al. (2014) and Snyder et al. (2017), we obtain similar trends but shifted to higher merger rate densities. The error bar on each point is computed by propagating the merger fraction and number density uncertainties on Eq. (9). At 1 ≲ z ≲ 5, Duncan et al. (2019) found that the volume-averaged merger rate is quite constant. On the other hand, from our data we find a slight decrease both at z   1 and at z >  4. At these early epochs, this difference could be caused by the poor constraints on the GSMFs adopted by Duncan et al. (2019) which result in large uncertainties on their data, making it impossible to draw robust conclusions at z ∼ 5. Nevertheless, our derived merger rate densities are in agreement, within the uncertainties, with other results derived in the literature. For example, Mundy et al. (2017) studied the evolution of the merger rate density up to z ∼ 3.5 for a large sample of log(M*/M⊙)> 10 galaxies. They found that, for close pairs with projected separations 5   rp   20 kpc, the ΓMM(z) evolution is better described by a power-law of the form Γ0(1 + z)γ, with 




Γ
0

=
1
.

64

−
0.41


+
0.58


×

10

−
4




$ \Gamma_0 = 1.64^{+0.58}_{-0.41} \times 10^{-4} $


 and 



γ
=


0.48


−
1.15


+
1.00




$ \gamma = {0.48}^{+1.00}_{-1.15} $


. We report their results, along with the uncertainties, in Fig. 6 and extrapolate them to the redshifts explored by ALPINE. As evident, our data points are comparable with the results by Mundy et al. (2017). If we also fit our merger rate densities (derived assuming the Kitzbichler & White (2008) merger timescale) with a power-law function we obtain Γ0 = (2.40 ± 0.63) × 10−4 and γ = −0.16 ± 0.23, that are consistent with the above outcomes. The power-law fit on the data computed with the timescales by Jiang et al. (2014) is in agreement with the Mundy et al. (2017) findings, as well. If we instead consider the results obtained with the Snyder et al. (2017) timescale, we find a rapid increase of the merger rate density with redshift, which departs from the upper envelope of Mundy et al. (2017) already at z ≳ 1.
Citation: Duncan et al. (2019)
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Citation: Duncan et al. (2019)
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Citation: Kitzbichler & White (2008)
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During this first gravity assist manoeuvre of Venus, the Solar Orbiter RPW instrument also detected dust impacts inside the planet’s induced magnetosphere (Fig. 10). In the absence of dedicated dust detectors, the electric antenna measurements provide the only opportunity to monitor dust particles in the space plasma environment. This method has been widely applied since the 1980s allowing to estimate the mass and size distribution of the impacting dust particles from the observed characteristics of the electric field signal (Gurnett et al. 1997; Meyer-Vernet 2001; Ye et al. 2014, 2018). One of the main mechanisms believed to convert the particle’s kinetic energy of the dust into an electrical signal is the impact ionization process which generates clouds of electrons and ions around the spacecraft body (Gurnett et al. 1983; Aubier et al. 1983; Meyer-Vernet 1985). Because of the very large relative velocity between the spacecraft and the particles, when a dust particle hits the spacecraft, it instantly vaporizes, forming a hot ionized gas with free electrons and positive or negative ions that expand away from the impact site (Drapatz & Michel 1974). These charged particles are hence attracted to, or repulsed from, the spacecraft surface depending on its electric potential relative to the surrounding ambient plasma. This induces an abrupt changes in the spacecraft potential which is then observed in the voltage data (e.g., escaping electrons generate a positive spacecraft signal). Recently, Mann et al. (2019) reviewed our current knowledge on dust antenna measurements, modeling works, and their prospect to inner heliospheric missions. Since TDS is designed to capture waveforms snapshots, it is well adapted to resolve voltage spikes associated with dust impacts. Thereby, Zaslavsky et al. (2021) provided a first analysis of dust measurements recorded by TDS, along Solar Orbiter’s orbit, with promising results on the impact rate and dust grains radial velocities.
Citation: Gurnett et al. 1983
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Citation: Mann et al. (2019)
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The Orion Bar is probably the best studied PDR in our Galaxy. It is located between the Orion Molecular Cloud 1 and the H ii region excited by the Trapezium cluster, and is exposed to an FUV field a few 104 times the mean interstellar radiation field. Owing to its proximity (417 pc, Menten et al. 2007) and nearly edge-on orientation, the Bar provides an ideal laboratory for testing PDR models (e.g., Jansen et al. 1995; Gorti & Hollenbach 2002; Andree-Labsch et al. 2017) and a primary target for observational studies of physical and chemical structures of PDRs (e.g., Tielens et al. 1993; Walmsley et al. 2000; van der Wiel et al. 2009; Arab et al. 2012; Peng et al. 2012; Goicoechea et al. 2016; Nagy et al. 2017). Observations of various molecular spectral lines have shown that the emissions could be better interpreted with an inhomogeneous density structure containing an extended and relatively low density (





 cm−3) medium and a compact and high-density (





 cm−3) component (e.g., Hogerheijde et al. 1995; Young Owl et al. 2000; Leurini et al. 2006, 2010; Goicoechea et al. 2016). However, due to the scarcity of high-resolution observations capable of spatially resolving the density structure, the nature of the high-density clumps or condensations is still not well understood. Lis & Schilke (2003) mapped the Bar in H13CN (1–0) with the Plateau de Bure Interferometer (PdBI) at an angular resolution of about 5″, and detected 10 dense clumps. They proposed that the H13CN clumps are in virial equilibrium and may be collapsing to form stars. Goicoechea et al. (2016) performed Atacama Large Millimeter/submillimeter Array HCO+ (4–3) observations of the Bar and detected over-dense substructures close to the cloud edge, and found that the substructures have masses much lower than the mass needed to make them gravitationally unstable. These two interferometric observations both target molecular spectral lines. A high-resolution map of the dust continuum emission of the Bar, which is highly desirable in constraining the mass and density of the dense condensations, is still lacking. Here we report our Submillimeter Array (SMA) observations of the dust continuum and molecular spectral line observations of the Bar.
Citation: Hogerheijde et al. 1995
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Citation: Jansen et al. 1995
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The majority of GPS pulsars are characterized by high dispersion measure (DM > 200 pc cm−3), which may very well be a coincidence of the specialized environments that harbour them. The conventional flux measurement techniques which rely on estimating the baseline level of the pulse profile may be affected by interstellar scattering which results in smearing of the pulse across the entire period. In some cases, when the pulse broadening time is a significant fraction of the pulse period (30 per cent or more) one can see a relatively sharp pulse, but at the same time the extended scattering tail may obscure the real baseline level, which leads to an underestimation of the pulsar flux. For pulsars with DMs in 200–300 pc cm−3 range this usually happens between 300 and 600 MHz (Lewandowski et al. 2013, 2015a). This leads to a somewhat pseudo-correlation between high DM and GPS pulsars (Kijak et al. 2007, 2011b) where serious underestimation of the flux at lower frequencies for high DM pulsars may give rise to an inverted spectra. The interferometric imaging technique provide a more robust measurement of the pulsar flux owing to the baseline lying at zero level thereby reducing errors made during the baseline subtraction. Dembska et al. (2015b), D15 hereafter, used the imaging technique to measure the flux of six high DM pulsars at 610 MHz to explore their suspected GPS nature. Their studies revealed that in four of the six cases the measured flux was underestimated due to scattering effects and the corrected flux followed a normal power-law spectra. In pulsar B1823−13 they confirmed the presence of GPS characteristics. However, the case of PSR B1800−21 defied expectations as the interferometric flux measurements turned out to be significantly lower than the earlier measurements using conventional methods. This gave rise to various questions regarding the spectral nature of this pulsar. There was also a possibility of the two measurement techniques being incompatible and errors during the measurement processes.
Citation: Kijak et al.; 2011b
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Citation: Dembska et al. (2015b)
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The HH 212 region in Orion (at 450 pc) can be considered an ideal laboratory to investigate the interplay of infall, outflow, and rotation in the earliest evolutionary phases of the star forming process. HH 212 is a low-mass Class 0 source driving a symmetric and bipolar jet extensively observed in typical molecular tracers such as H2, SiO, and CO (e.g. Zinnecker et al. 1998). High-spatial resolution observations (down to \hbox{${\simeq}0\farcs3{-}0\farcs4$}≃ 0 .̋ 3−0 .̋ 4) performed with the SubMillimeter Array (SMA; Lee et al. 2006, 2007a, 2008), the IRAM Plateau de Bure (PdB) interferometer (Codella et al. 2007; Cabrit et al. 2007, 2012), and the Atacama Large Millimeter Array (ALMA; see Lee et al. 2014; Codella et al. 2014a) reveal the inner ± 1″−2″ = 450−900 AU collimated jet (width ≃100 AU) close to the protostar. HH 212 is also associated with a flattened rotating envelope in the equator perpendicular to the jet axis observed firstly with the NRAO Very Large Array (VLA) in NH3 emission by Wiseman et al. (2001) on 6000 AU scales. More recent SMA and ALMA observations in the CO isotopologues and HCO+ on ~2000, 800 AU scales indicates that the flattened envelope is rotating and infalling onto the central source, and can therefore be identified as a pseudo-disk according to magnetised core collapse models (Lee et al. 2006, 2014). In addition, a compact (≤120 AU), optically thick dust peak is observed by Codella et al. (2007), Lee et al. (2006, 2014) and attributed to an edge-on disk rather than the inner envelope. This seems to be confirmed by HCO+ and C17O emission showing signatures of a compact disk of radius ~90 AU Keplerian rotating around a source of ≃0.2−0.3 M⊙ (Lee et al. 2014; Codella et al. 2014a). Keplerian rotating disks had previously only been observed towards other three Class 0 objects: IRAS 4A2 (Choi et al. 2010), L1527 (Tobin et al. 2012; Sakai et al. 2014), and VLA1623A (Murillo et al. 2013), but HH 212 can be considered as the only object clearly revealing both a disk and a fast collimated jet, calling for further observations aimed to characterise its inner regions.
Citation: Codella et al. 2014a
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Citation: Codella et al. 2014a
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Citation: Zinnecker et al. 1998
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Citation: Wiseman et al. (2001)
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Figure 3 shows rough upper limits of the 56Ni yields from NDAFs with outflows (blue shaded region) and CCSNe (the red and green shaded regions shows the conditions of [Mg/Fe] = 0 and [O/Fe] = 0 and explosion energies in the range of 1–100 or 150 B) as functions of the progenitor-star mass. The black lines denote the medians of these regions. The CCSN data are adopted from Umeda & Nomoto (2008), because it is believed that the abundances of the most metal-poor halo stars satisfy the conditions [Mg/Fe] ≥ 0 and [O/Fe] ≥ 0, according to observations. That means for [Mg/Fe]  0 or [O/Fe]  0, the 56Ni yields should be less than those shown in Figure 3 (Umeda & Nomoto 2008). It should be mentioned that the shaded regions in Figure 3 just reflect the rough upper limits of the 56Ni yields; or rather, the ability of CCSNe and NDAFs to synthesize 56Ni, because we set the terms for the fall-free approximation of the density profile, p ≥ 0.3, for the NDAF outflows, and [Mg/Fe] = 0 and [O/Fe] = 0 for the CCSNe. More importantly, contrary to energetic CCSNe requiring a high explosion energy, the BH-mass growth (i.e., fallback accretion) favors the condition of a low explosion energy. In other words, there is energy and matter competition between CCSN explosions and BH fallback accretion. Hence, Figure 3 indicates that the upper limits of the total 56Ni yields should depend weakly upon the explosion energy. Hypernova models can increase 56Ni yields by ten times or more relative to normal CCSNe (e.g., Nomoto et al. 2004), and have been included to investigate the galactic evolution of SN rates (e.g., De Donder & Vanbeveren 2003). In such energetic explosions, fallback accretion is generally inefficient. As well as the hypernova models (e.g., Kobayashi et al. 2020), we consider that nucleosynthesis in the NDAF outflows in the centers of faint or failed CCSNe is another plausible way to explain observations of the metal abundance in our neighborhood and the chemical evolution of galaxies. Moreover, Kobayashi et al. (2020) estimated that the proportion of failed SNe was perhaps as large as 50% early in the history of the Galaxy, which might support the consequence of the NDAF outflows on nucleosynthesis.
Citation: Umeda & Nomoto (2008)
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Citation: Umeda & Nomoto 2008
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