adsabs/FOCAL huggingface dataset:
The discovery of GW170817 and its electromagnetic counterparts (GRB170817A and AT2017gfo; Abbott et al. 2017a; Coulter et al. 2017; Goldstein et al. 2017) ushered in a new era of multimessenger astrophysics, in which both gravitational waves and photons provide complementary views of the same source. While observations at optical and infrared wavelengths unveiled the onset and evolution of a radioactive-powered transient, known as kilonova, observations at X-rays and, later, radio wavelengths probed a different component of emission, likely originated by a relativistic outflow launched by the merger remnant. Troja et al. (2017) explained the observed X-ray and radio data as the onset of a standard short GRB (sGRB) afterglow viewed at an angle (off-axis). However, as already noted in Troja et al. (2017) and Kasliwal et al. (2017), a standard top-hat jet model could explain the afterglow data set collected at early times, but failed to account for the observed gamma-ray emission. Based on this evidence, Troja et al. (2017) suggested that a structured jet model (e.g. Zhang et al. 2004; Kathirgamaraju, Barniol Duran & Giannios 2018) provided a coherent description of the entire broad-band data set. Within this framework, the peculiar properties of GRB170817A/AT2017gfo could be explained, at least in part, by its viewing angle (see also Lamb & Kobayashi 2017; Lazzati et al. 2017). An alternative set of models invoked the ejection of a mildly relativistic wide-angle outflow, either a jet-less fireball (Salafia, Ghisellini & Ghirlanda 2018) or a cocoon (Nagakura et al. 2014; Hallinan et al. 2017). In the latter scenario, the jet might be chocked by the merger ejecta (Mooley et al. 2017), and the observed gamma-rays and broad-band afterglow emission are produced by the expanding cocoon. The cocoon may be energized throughout its expansion by continuous energy injection. In this paper detailed models of structured jet and cocoon, from its simplest to more elaborate version, are compared with the latest radio to X-ray data. Predictions on the late-time evolution are derived, and an unambiguous measurement capable of disentangling the outflow geometry, jet versus cocoon, is presented.
Citation: Zhang et al. 2004
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We further constrain the stellar parameters for HD 85628 using the Virtual Observatory SED Analyzer (VOSA)5 and fitting the Hα profile of the star’s CHIRON spectrum. We fit the spectral energy distribution (SED; Fig. 8) of HD 85628 using published photometry from Tycho (BT VT; ESA 1997), APASS (BV; Henden et al. 2016), Gaia DR2 (BpRpG; Gaia Collaboration 2018), DENIS (JK; Epchtein et al. 1994), 2MASS (JHKs; Skrutskie et al. 2006), and WISE (W1W2W3W4; Wright et al. 2010), and fit Kurucz ATLAS9 stellar atmosphere models (Castelli & Kurucz 2003). Given that the star is clearly main sequence and relatively young ( 1 Gyr), we constrain the surfacegravity to be within ±0.5 dex of log g = 4.0 and metallicity within ±0.5 dex of solar, and include the extinction and 1σ uncertainty presented previously as a constraint, but allow the effective temperature to float. We find the best-fit parameters to be for a Kurucz model with Teff, = 7844

$^{57}_{-285}$−285+57
 K, log g = 4.0, and solar metallicity. We also fitted the shape of the Hα line from the average high-resolution CHIRON spectra with a grid of Kurucz spectra (as used above). While we fail to meaningfully constrain its metallicity and surface gravity in this way, the spectral line shape is consistent with a temperature of 7700 ± 300 K. Based on these independentanalyses, we adopt Teff ≃ 7800 ± 200 K. We note that this is somewhat cooler than expected given the A3V classification by Houk & Cowley (1975), since typical A3V stars have Teff ≃ 8550 K (Pecaut & Mamajek 2013), however we cannot reconcile such a hot temperature given the available data, leading us to believe that the initial classification was incorrect, and that this star is in fact an A7V star. The best-fit luminosity to SED fit using the VO Sed Analyzer (VOSA) tool, and adopting the distance based on the Gaia DR2 trigonometric parallax, is L = 12.23 ± 0.0655 L⊙ or log (L∕L⊙) ≃ 1.087 ± 0.023 dex. For the adopted effective temperature, this implies that HD 85628 has a radius of 1.92 ± 0.11 R⊙ 6.
Citation: Castelli & Kurucz 2003
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The optical, spectrocopic and infrared remote imaging system (OSIRIS) scientific imaging cameras on the Rosetta spacecraft have been monitoring the coma activity of comet 67P Churyumov–Gerasimenko (67P hereafter) since their orbital rendezvous in 2014 August (Lara et al. 2015; Lin et al. 2015; Sierks et al. 2015; Lin et al. 2016; Shi et al. 2016; Vincent et al. 2016a,b). The solar heating of the sunlit side of the nucleus surface leads to sublimation of the volatiles and to the formation of dust jets. On 2015 March 12, a small outburst was first detected from a part of the Imhotep region on the night side (Knollenberg et al. 2016). Such mini-outbursts or night-side activities have been observed before at comet 9P/Tempel 1 by the Deep Impact mission (Farnham et al. 2007, 2013) and comet 103P/Hartley 2 by the EPOXI mission (A’Hearn et al. 2011; Bruck Syal et al. 2013). Shortly before the close approach to comet 9P/Tempel 1, the high-resolution camera on the Deep Impact spacecraft found a number of small, well-defined jets whose bases were rooted at the nucleus surface. Some of these, called limb jets, appeared to come from the darker regions and appeared to be associated with the ice patches reported by Sunshine et al. (2006). A later mission of the Stardust–New Exploration of comet Tempel 1 (NExT) imaging of 9P/Tempel 1 allowed us to connect the jets with cliffs (Farnham et al. 2013). Comet 103P/Hartley 2 also displayed several narrow jet features emitting from the un-illuminated regions beyond the terminator at the time of the flyby observations (Bruck Syal et al. 2013). Unlike the less certain identification of the source regions on Tempel 1, the source region of the night-side jets of 103P/Hartley 2 could be clearly traced to some rough surface topography. However, the mechanism for this type of activity is still unknown. Fortunately, unlike the snap shots from the previous flyby observations, the OSIRIS measurements can provide precise information on the timing and location of the outbursts via a time series of high-resolution images. After the first detection in 2015 March, the OSIRIS wide-angle camera (WAC) and narrow-angle camera (NAC) captured another outburst in mid-July of 2015. Since then, many more outbursts from the night-side and sunlit regions have been detected (Feldman et al. 2016; Grün et al. 2016), with most of their source regions located in the Southern hemisphere of comet 67P (Vincent et al. 2016a). The detected outburst events show a variety of morphological features that can be classified into three different types: broad fans, narrow jets and complex plumes. In this work, we investigate the morphology of these events and characterize their physical properties in detail, including the surface brightness profiles, ejected mass and speed if there are two or more sequential images acquired by the same filter in short duration during the time frame of the outburst.
Citation: A’Hearn et al. 2011
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Small grains, which contribute most to infrared emission, are removed by collisional fragmentation and blown out by radiation pressure. The removal timescale is much shorter than the ages of host stars. Disruptive collisions among underlying large bodies, which are called planetesimals, produce smaller bodies and collisional fragmentation among them results in even smaller bodies. This collisional cascade continues to supply small grains. The evolution of debris disks has been explained by the steady-state collisional cascade model (e.g., Wyatt 2008; Kobayashi & Tanaka 2010): the total mass of bodies decreases inversely proportional to time t. Therefore, the excess ratio (Fdisk/F∗) is given by (2)\begin{equation} \frac{F_{\rm disk}}{F_{*}} = \frac{t_0}{t},\label{cc} \end{equation}FdiskF∗=t0t,where t0 is the dissipation timescale that is determined by the collisional cascade. Under the assumption of the steady state of collisional cascade, the power-law size distribution of bodies is analytically obtained and the power-law index depends on the size dependence of the collisional strength of bodies (see Eq. (32) of  Kobayashi & Tanaka 2010). In the obtained size distribution, erosive collisions are more important than catastrophic collisions (see Fig. 10 of Kobayashi & Tanaka 2010). Taking into account the size distribution and erosive collisions, we derive t0 according to the collisional cascade (see Appendix E for derivation), (3)\begin{eqnarray} t_0&amp;\sim&amp; 1.3 \left( \frac{s_{\rm p}}{\rm 3000\,km} \right)^{0.96} \left( \frac{R}{\rm 2.5\,au} \right)^{4.18}\nonumber\\ &amp;&amp;\quad\times \left(\frac{\Delta R}{0.4 R}\right) \left( \frac{e}{\rm 0.1} \right)^{-1.4} {\rm Gyr},\label{eq:t0} \end{eqnarray}t0~1.3sp3000 km0.96R2.5 au4.18where sp is the size of planetesimals, R is the radius of the planetesimal belt, and e is the eccentricity of planetesimals. Interestingly, t0 is independent of the initial number density of planetesimals (Wyatt et al.  2007). Note that the perturbation from Moon-sized or larger bodies is needed to induce the collisional fragmentation of planetesimals (Kobayasi & Löhne 2014), which is implicitly assumed in this model.
Citation: Kobayashi & Tanaka 2010
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Citation: Kobayashi & Tanaka 2010
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First direct evidence for the geometrical distribution of the dust was found by Jaffe et al. (2004) with the help of the mid-infrared interferometric instrument (MIDI; Leinert et al. 2003) at the Very Large Telescope Interferometer (VLTI). One of the best-studied parsec-sized dust distribution is harboured by the Circinus galaxy, which is the closest (4.2 Mpc, 1 arcsec ≈20 pc; Freeman et al. 1977) and the second brightest Seyfert galaxy in the MIR. High-resolution mid-infrared (MIR) interferometric observations have revealed a two-component morphology in the brightness distribution: (i) a larger scale, elongated component in direction of the ionization cone (along PA ≈ 107°) with a full-width at half-maximum (FWHM) size of roughly 0.8 × 1.9 pc, which is responsible for 80 per cent of the total MIR flux and was interpreted either as the directly illuminated funnel walls of the dusty molecular torus or as part of the (filamentary/clumpy) outflow; (ii) a disc-like component with an FWHM size of roughly 0.2 × 1.1 pc and elongated along PA ≈ 46° (Tristram et al. 2007, 2014). Both components have a dust temperature of roughly 300 K. The disc-like component was modelled by two Gaussian emitters (a highly elongated emitter plus an unresolved source) in the simple model used by Tristram et al. (2014). This was interpreted as signs for a more complex structure as well as for asymmetry in the second component. The orientation and size of the disc-like component coincides with an edge-on warped disc seen in maser emission with the help of very long baseline interferometry traced by H2O masers (Greenhill et al. 2003). It has an outer radius of roughly 0.4 pc. A similar picture emerges for NGC 1068: A hot parsec-scale disc (FWHM ≈1.35 × 0.45 pc, T ≈ 800 K) was found with similar orientation and extent as the H2O maser disc (Greenhill et al. 1996; Greenhill & Gwinn 1997). It is surrounded by warm dust extended in polar direction with an FWHM ≈3 × 4 pc and a temperature T ≈ 300 K (Jaffe et al. 2004; Raban et al. 2009). However, in a systematic study of a larger sample of objects a large range of properties of the dust distribution has been found (Burtscher et al. 2013).
Citation: Tristram et al. 2007
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Compact symmetric objects are very powerful (P1.4 GHz > 1025 W Hz−1), compact (linear size of 50–100 pc), and young (≲104 yr) objects with a rather symmetric radio structure and convex synchrotron radio spectra (Wilkinson et al. 1994; Murgia 2003; Polatidis & Conway 2003). The characterized convex synchrotron radio spectrum peaks at around 100 MHz in the case of compact steep spectrum (CSS) sources, at about 1 GHz in the case of GHz-peaked spectrum (GPS) objects, and up to a few GHz (e.g., 5 GHz) in the case of high-frequency peakers (HFPs; Dallacasa et al. 2000). The turnover is explained as synchrotron self-absorption (SSA) affecting in a small radio-emitting region or the free-free absorption (FFA) by the dense ambient medium. In a “young scenario”, as the source grows, the inner region (possibly a tiny radio lobe) expands, and as a result, the turnover frequency moves to lower frequencies. In this scenario, the HFPs are newborn radio sources that develop into extended radio sources (e.g., FR I, FR II) after evolving through GPS and CSS stages. It is possible that the activity is recurrent in at least some sources: there have been observations of faint extended emission around a few GPS sources (e.g., Baum et al. 1990; Stanghellini et al. 1990; Marecki et al. 2003). The extended emission could be a relic of an earlier active period, into which the reborn radio jets are expanding. Another popular explanation for the turnover and compact natures of CSS, GPS, and HFP is the “frustration” hypothesis. This theory argues that these sources are confined in small spatial scale and high-density environments, and as a consequence the radio emission is frustrated by the abundant nuclear plasma (van Breugel et al. 1984; Peck et al. 1999; Tingay & de Kool 2003; Callingham et al. 2015; Tingay et al. 2015). In addition, An & Baan (2012) also proposed that young sources with strong constant AGN power breaking through the dense inner region of the host galaxy could result in the compact morphology and the turnover properties of CSOs.
Citation: Dallacasa et al. 2000
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SN 2011fe, discovered a mere ≈11 h after explosion (Nugent et al. 2011) by the Palomar Transient Facility (PTF; Law et al. 2009), is the brightest SN Ia since the advent of modern astronomical detectors. Located at just $d_L \approx 6.5~\rm {Mpc}$ (e.g. Shappee & Stanek 2011; Beaton et al. 2019), SN 2011fe exploded in a region of M101 uncontaminated by intervening dust (Patat et al. 2013) providing an ideal location for testing SN Ia progenitor and explosion models. The early detection allowed extensive follow-up observations across the electromagnetic spectrum (e.g. Matheson et al. 2012; Parrent et al. 2012; Pereira et al. 2013; Hsiao et al. 2013; Johansson, Amanullah & Goobar 2013; Tsvetkov et al. 2013; Munari et al. 2013; Mazzali et al. 2014; Zhang et al. 2016) and provided direct constraints on the radius of the exploding star (Nugent et al. 2011; Bloom et al. 2012). Stringent non-detections in radio (Chomiuk et al. 2012; Horesh et al. 2012; Kundu et al. 2017) and X-ray (Horesh et al. 2012; Margutti et al. 2012) observations exclude nearby CSM at high significance. Early ultraviolet (UV) photometry did not show any evidence for the ejecta encountering a nearby companion star (Brown et al. 2012) and nebular spectra lacked the Balmer emission lines from material ablated off the donor star by the ejecta impact (Shappee et al. 2013b; Lundqvist et al. 2015; Tucker et al. 2022). Pre-explosion imaging excludes the presence of a RG or He donor star (Li et al. 2011) and disfavor an accreting WD in the ∼105 yr prior to explosion (Graur, Maoz & Shara 2014). Multi-epoch spectropolarimetry reveal consistently-low continuum polarization suggestive of a symmetric ejecta distribution with evidence for minor oblateness (Milne et al. 2017). Finally, nebular-phase observations at ≳ 1 year after maximum light allows a direct view to the inner ejecta and provides unique constraints on the explosion conditions (McClelland et al. 2013; Kerzendorf et al. 2014, 2017; Mazzali et al. 2015; Graham et al. 2015; Taubenberger et al. 2015; Dimitriadis et al. 2017; Friesen et al. 2017; Shappee et al. 2017; Tucker et al. 2022). SN 2011fe is one of the best-studied astronomical objects in the past decade and remains a key benchmark for any SN Ia theory or model.
Citation: Kundu et al. 2017
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A closer look at the known ejecta-dominated SNRs supports the role of surrounding winds and/or shells, and may provide additional insight into why such remnants are so rare. Several, and perhaps all of them, are ones where the ejecta are expanding into a pre-SN stellar wind from the progenitor, or into a cavity carved out by such winds. The clearest case is for Cas A, where the light-echo spectrum of the actual SN that shows it to have been a Type IIb event (Rest et al. 2008; Krause et al. 2008). These are produced from the collapse of the helium core of a red supergiant that had lost most of its hydrogen envelope before exploding, so the ejecta expand into the stellar wind from the pre-SN star (Chevalier & Oishi 2003; Orlando et al. 2016). The extreme luminosity of NGC4449-1 has been best explained by its expansion into a dense and extensive circumstellar environment produced by winds from its massive progenitor, possibly with additional contributions due to winds from other massive stars in the surrounding dense OB cluster (Milisavljevic & Fesen 2008). For G292.0+1.8 and E0102–7219, the fact that fast knots of ejecta are expanding ballistically 2000–3000 yr after the explosion requires that they must be expanding into low-density cavities—ones evacuated by pre-SN winds. In both cases, there is an outer shell of X-ray emission where the SN blast wave is interacting with the CSM. As with Cas A, this interaction also leads to the reverse shock that excites the dense fragments of ejecta, producing the optical emission. For both Puppis A and N132D, spectra of the outer radiative filaments show them to be very high in nitrogen; these too are likely overtaking winds enriched by dredged-up nitrogen. These stripped-envelope SNe—types Ib and Ic—are relatively rare compared to their cousins, types II and IIL, that explode with their envelopes more or less intact; the recent review by Smartt (2009) indicates that together SN Ib and Ic comprise only ∼20%–30% of core-collapse events.
Citation: Orlando et al. 2016
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In this work, we investigate how the climate of an Earth-like planet is affected when its orbit is perturbed by the presence of a nearby giant planet. For the first time, a GCM coupled with analytical equations that describe the orbital evolution of a terrestrial planet are used. An additional major difference between our work and previous studies is that we utilize a fully coupled ocean model and an Earth continental layout. This is in contrast to WP2002 who used a 50 m “thermodynamic slab” ocean model without horizontal ocean heat transport or Linsenmeier et al. (2015), who used an aquaplanet model and a 50 m slab ocean, but again with no horizontal ocean heat transport. We use a fully coupled ocean model because alongside atmospheric heat transport, ocean heat transport plays a vital role in the climate of Earth (Peixoto & Oort 1992). In particular, the work of Hu & Yang (2014) has shown that the effects of a fully coupled ocean versus a shallow slab ocean can be significant when looking at synchronously rotating worlds around M-dwarf stars. Godolt et al. (2015) demonstrated stark differences for planets orbiting F-type stars when changing ocean heat transport, while Rose (2015) nicely demonstrated the climatic effects of changing ocean heat transport equations for aqua-type and ridge-type worlds. The downside of a fully coupled ocean approach is that it can take hundreds of model years for a fully coupled ocean to come into equilibrium with the atmosphere. Yet, it will provide a more accurate picture of the climate of the world being modeled. In this study we focus on the effects of the terrestrial planet’s orbital eccentricity on the planet’s climate, which is an under-researched area in 3D GCM studies. At the same time, we keep θp = 235, following for modern Earth. The latter is a necessary requirement for comparing with past and future work in the literature since obliquity plays such an important role in the possible climate states of terrestrial planets.
Citation: Peixoto & Oort 1992
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Phosphorus, which is isoelectronic with both nitrogen and the CH group, is a key element of living systems as a major component of nucleic acids and nucleotides, performing many relevant biochemical functions (Pasek & Lauretta 2005). Conversely, despite significant progress in the recent years (Jiménez-Serra et al. 2018; Rivilla et al. 2018; Fontani et al. 2019; Chantzos et al. 2020) and its importance to astrobiology, the interstellar chemistry of phosphorus is still poorly understood. The first identified phosphorus compound in the ISM was PN through observations of its rotational transitions in Orion-KL, W51M, and Sgr B2 (Turner & Bally 1987; Ziurys 1987). This observation was followed by the detection of free CP in the carbon star envelope IRC +10216 (Guelin et al. 1990). The other phosphorus-bearing molecules detected so far are HCP (Agúndez, Cernicharo & Guélin 2007), CCP (Halfen, Clouthier & Ziurys 2008), PO (Tenenbaum, Woolf & Ziurys 2007), and PH3 (Agúndez et al. 2014b), while a tentative detection of NCCP is also reported (Agúndez, Cernicharo & Guélin 2014a). Phosphorus was also detected in the coma of the comet 67P/Churyumov–Gerasimenko (Altwegg et al. 2016), with recent analysis indicating PO as its main carrier (Rivilla et al. 2020). In addition, PH3 was recently detected in the cloud decks of Venus through millimetre waveband observations (Greaves et al. 2020). Larger phosphorus-bearing molecules, such as phosphorus oxoacids (Turner et al. 2018a) and alkylphosphonic acids (Turner et al. 2018b) – the latter detected in the Murchison meteorite (Cooper, Onwo & Cronin 1992) – were identified in PH3-doped interstellar ice analogues exposed to ionizing radiation. These results, in combination with the increasing literature on phosphorus-bearing molecules in circumstellar envelopes (Ziurys, Schmidt & Bernal 2018) and solar-type star-forming regions (Lefloch et al. 2016) and protostars (Lefloch et al. 2018; Bergner et al. 2019), suggest that their role in the ISM might be greater than previously thought.
Citation: Ziurys 1987
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