adsabs/FOCAL huggingface dataset:
The past two decades have seen rapid progress in the field of solar magnetoseismology (SMS; for recent reviews, see e.g., Nakariakov & Verwichte 2005; Banerjee et al. 2007; De Moortel & Nakariakov 2012; Nakariakov et al. 2016; Wang 2016). Among the rich variety of low-frequency waves observed in the Sun’s atmosphere, flare-related quasi-periodic fast propagating wave trains have received much attention (see Liu & Ofman 2014, for a recent review). Their quasi-periods usually range from 25 to 400 s. These wave trains were discovered (Liu et al. 2011) and extensively observed in images acquired with the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO/AIA; Liu et al. 2012; Shen et al. 2013; Yuan et al. 2013; Nisticò et al. 2014; also see Lemen et al. 2012 for a description of the instrument). On the other hand, quasi-periodic signals in coronal emissions presumably from density-enhanced loops have been known since the 1960s (e.g., Frost 1969; Parks & Winckler 1969; Rosenberg 1970; McLean & Sheridan 1973; see Table 1 of Aschwanden et al. 1999 for a comprehensive compilation of measurements prior to 2000). The quasi-periods P of a considerable fraction of these signals were of the order of seconds. While these measurements were largely spatially unresolved, more recent high-cadence instruments imaging the corona at total eclipses indicated the presence in coronal loops of quasi-periodic signals both with 





 s (Williams et al. 2001, 2002; Katsiyannis et al. 2003) and with 





 s (Samanta et al. 2016). In addition, quasi-periodic pulsations in the lightcurves of solar flares with similar periods have also been measured using imaging instruments such as the Nobeyama Radioheliograph (e.g., Asai et al. 2001; Nakariakov et al. 2003; Melnikov et al. 2005; Kupriyanova et al. 2013), SDO/AIA (e.g., Su et al. 2012), and more recently with the Interface Region Imaging Spectrograph (IRIS; Tian et al. 2016; see also De Pontieu et al. 2014 for a description of IRIS).
Citation: Liu et al. 2012
Citation function: Background; Background; Background
The room-temperature millimeter wave rotational spectrum of ethyl isocyanate in Fig. 1 presents an exceptionally high line density. Its analysis was started using predictions from the spectroscopic constants obtained in the previous microwave works (Heineking et al. 1994; Kasten et al. 1983; Sakaizumi et al. 1976) for the stable cis configuration. It is characterized by a relatively large dipole moment along the a inertial axis (|µa| = 2.81 D and |µb| = 0.03 D (Sakaizumi et al. 1976), Cs symmetry, and dihedral angle τ(C–C–N = C) = 0◦ (see Fig. 1). The identification of Ka = 0 and lower-frequency Ka = 1 transitions, originating from J0 J and J1 J energy levels, was relatively straightforward and their assignment and analysis could be easily expanded up to 340 GHz (J˝ = 64) with the help of the Loomis-Wood-type plot technique from the AABS package (Kisiel et al. 2005) and SP-FIT/SPCAT program suite (Pickett 1991). The upper-frequency Ka = 1 transitions (J1 J−1 levels), which became degenerate with Ka = 2 transitions (J2 J−1 levels) for J˝ > 45, were subsequently localized, however, their analysis quickly ran into problems. As shown in Fig. 2, significant departures from the predicted positions were observed at high J˝ even though it was clear from the Loomis-Wood-type plots that the assignments were correct. Similar situations also occurred for higher Ka transitions and with increasing value of Ka, the limit of J up to which the rotational transitions were amenable to the simple semirigid-rotor Hamiltonian analysis, was decreasing (see Fig. 2). Only those transitions that supported the semirigid-rotor treatment were retained in the analysis. These transitions were finally combined with hyperfine-free transitions (5–24 GHz, J˝ = 0−7, K˝a = 0−3) from Heineking et al. (1994) and globally fitted using Watson’s S -reduced Hamiltonian in Ir representation. The adjusted rotational and centrifugal distortion constants are given in Table 1. The list of experimental frequencies is provided in the Table 4. Finally, the deviation trends observed in the Loomis–Wood type plots, such as those in Fig. 2, were advantageously followed to measure the frequencies of more than 200 transitions that could not be encompassed in the semirigid rotor fit. These transitions are collected in the Table 5.
Citation: Pickett 1991
Citation function: Future Work; Future Work
AGN feedback can exist in several forms such as radiation, thermal, or non-thermal (cosmic rays) pressure-driven winds, jet-mode feedback, and via magnetic forces on accretion disc scales. AGN feedback can explain several observed properties such as the presence of high velocity (>1000 km s−1) multiphase gas outflows in low and high redshift galaxies and observations of bubbles or cavities in X-ray observations of galaxy clusters (e.g. Blanton et al. 2011; Fabian 2012; Sanders et al. 2014; Feruglio et al. 2015; Laha et al. 2021). High velocity outflows from AGN host galaxies have been reported in numerous studies in the literature (see Veilleux et al. 2020 for a review and the references therein) using optical spectroscopy (e.g. Greene et al. 2011; McElroy et al. 2015; Sun, Greene & Zakamska 2017; Durré & Mould 2018; Manzano-King, Canalizo & Sales 2019; Perna et al. 2020; Santoro et al. 2020; Trindade Falcão et al. 2021), near-infrared spectroscopy (e.g. Kakkad et al. 2016; Zakamska et al. 2016; Bischetti et al. 2017; Diniz et al. 2019; Riffel, Zakamska & Riffel 2020a; Riffel et al. 2020b) and sub-mm spectroscopy (e.g. Michiyama et al. 2018; Zschaechner et al. 2018a; Audibert et al. 2019; Impellizzeri et al. 2019; García-Bernete et al. 2021). One of the key quantities that is not well understood through these observations is how efficiently does the outflow couple with the ISM (e.g. Harrison et al. 2018). The coupling efficiency i.e. the ratio between the kinetic power of the outflow ($\dot{E}_{\rm kin}$) and the bolometric luminosity of the AGN (Lbol) or the star formation rate (SFR) of the host galaxy is critical to quantify the true impact of AGN feedback on host galaxies – the higher the efficiency, the easier it is for these outflows to heat the gas or propagate the outflows to the galaxy outskirts. An accurate measurement of mass outflow rate and kinetic energy is therefore necessary to estimate the true coupling efficiency, which can also be used as constraints in cosmological simulations.
Citation: McElroy et al. 2015
Citation function: Background; Background
The large Jovian irregular satellites have been observed and analyzed using their light curves, colours, and reflectance spectra but the reported measurements are sometimes contradictory. The multicolour observation of some retrograde and prograde Jovian irregular satellites by Tholen & Zellner (1984) suggested C-class surface composition for prograde and more diverse colours for the retrograde families with a mixture of C- and D-type spectra. They noted that Carme had a flat visible wavelength reflectance spectrum, but with a strong upturn in the ultraviolet. Tholen & Zellner (1984) suggested that Carme might be showing low-level cometary activity with CN emission at 0.388 μm. Luu (1991) identified C- and D-type asteroid spectral features for both prograde and retrograde families based on spectroscopic observations of JV-JXIII and suggested them to be similar to Jupiter’s Trojan asteroids. Based on 1.3–2.4 μm near-IR (NIR) observations, Brown (2000) reported their compositions as being similar to P- and D-class asteroids from the outer asteroid belt, while their visible spectra resemble C-class asteroids. Cruikshank (1977) and Degewij et al. (1980) observed Himalia in the NIR and confirmed that its surface composition is similar to that of C-type asteroids. Brown (2000) concluded that NIR spectra of Himalia and Elara are featureless between 1.4 and 2.5 μm and do not contain any water-ice absorption features. Subsequently, Brown & Rhoden (2014) supported these findings and suggested that these objects lacked aqueously altered phyllosilicates based on the absence of a 3 μm absorption band. Brown et al. (2003) and Chamberlain & Brown (2004) studied Himalia using data acquired by the Visual and Infrared Mapping Spectrometer (VIMS) on-board Cassini spacecraft during Jupiter’s fly-by and found that its spectrum (0.3–5.1 μm) has low reflectance, a slight red slope, and an apparent absorption near 3-μm suggesting the presence of water in some form. In addition, Jarvis et al. (2000) reported a weak absorption at 0.7 μm in Himalia’s spectrum and attributed it to oxidized iron. Contrary to this result, Brown & Rhoden (2014) found no evidence for aqueously altered phyllosilicates in the 2.2–3.8 μm region.
Citation: Luu (1991)
Citation function: Background
The observational and theoretical studies of nitrogen isotope fractionation in star-forming regions can help to constrain nitrogen chemistry. Nitrogen has two stable isotopes, 14N and 15N. The elemental abundance ratio [14N/15N]elem in the local interstellar medium (ISM) has been estimated to be ~200–300 from the absorption line observations of N-bearing molecules toward diffuse clouds (Lucas & Liszt 1998; Ritchey et al. 2015). L1544 is a prototypical prestellar core located in the Taurus molecular cloud complex. In L1544, the 14N/15N ratio of several different molecules has been measured: 






14




N


2




H


+


=


920


−
200


+
300


,



14




N


2




H


+


/


NNH


+


=


1000


−
220


+
260




$ {}^{14}{\mathrm N}_2\mathrm H^+=920_{-200}^{+300},^{14}{\mathrm N}_2\mathrm H^+/\mathrm{NNH}^+=1000_{-220}^{+260} $


 (Bizzocchi et al. 2013; Redaelli et al. 2018), NH2D/15NH2D > 700 (Gérin et al. 2009), CN/C15N = 500 ± 75 (Hily-Blant et al. 2013b), and HCN/HC15N = 257 (Hily-Blant et al. 2013a). Among the measurements, the significant depletion of 15N in N2H+ is the most challenging for the theory of 15N fractionation. In general, molecules formed at low temperatures are enriched in 15N through gas-phase chemistry triggered by isotope exchange reactions (e.g., Terzieva & Herbst 2000). A 15N-bearing molecule has a slightly lower zero-point energy than the corresponding 14N isotopolog. This results in endothermicity for the exchange of 15N for 14N, which inhibits this exchange at low temperature enabling the concentration of 15N in molecules. Astrochemical models for prestellar cores, which consider a set of nitrogen isotope exchange reactions, have indeed predicted that atomic N is depleted in 15N, while N2 (and thus N2H+) is enriched in 15N (e.g., Charnley & Rodgers 2002). The model prediction clearly contradicts the observation of the N2H+ isotopologs in L1544. The 15N depletion in N2H+ was recently found in other prestellar cores as well, such as L183, L429, and L694-2 (Redaelli et al. 2018). Furthermore, Roueff et al. (2015) recently pointed out the presence of activation barriers for some key nitrogen isotope exchange reactions, based on their quantum chemical calculations. Then 15N fractionation triggered by isotope exchange reactions may be much less efficient than previously thought (Roueff et al. 2015, but see also Wirström & Charnley 2018).
Citation: Hily-Blant et al. 2013b
Citation function: Uses; Uses
Currently, this 53Mn–53Cr age of 4566.6 ± 0.6 Ma for crystallization for EC 002 represents the oldest record of volcanism in the Solar system. For example, the oldest crust formation of Earth and Moon only dates back to ∼4.3–4.4 Ga (O’Neil & Carlson 2017; Borg et al. 2019), and Mars, Vesta, and the angrite and main-group aubrite parent bodies show ages of mantle–crust differentiation at ∼4547 Ma (Bouvier et al. 2018), 4564.8 ± 0.6 Ma (Trinquier et al. 2008), 4563.2 ± 0.2 Ma (Zhu et al. 2019b), and 4562.5 ± 1.1 Ma (Zhu et al. 2020b), respectively. The crystallization age of EC 002 also predates all those of the other dated achondrites, such as angrites (Amelin 2008a, b; Connelly et al. 2008), ureilites (Goodrich et al. 2010; Bischoff et al. 2014), NWA 8704/6693, NWA 11119 (Srinivasan et al. 2018), and NWA 7325 (Koefoed et al. 2016). The result strongly supports the notion that advanced silicate differentiation occurred and evolved planetary crust formation very early in the Solar system, i.e. within the first 1 Ma after CAI formation (4567.3 ± 0.1 Ma; Amelin et al. 2010; Connelly et al. 2012). The crystallization of andesitic crust must post-date both accretion and core formation on the EC 002 parent body, which is also consistent with evidence for early core formation for some asteroids derived from some iron meteorites (Kruijer et al. 2014; Anand et al. 2021). The age for EC 002 is older than some of the chondrule formation ages (Connelly et al. 2012; Bollard et al. 2017; Zhu et al. 2020b). This observation supports previous suggestions that many chondrites and their components reflect younger nebular processes, post-dating the oldest differentiated planetesimals, such as the EC 002 parent body. Thus, chondrules may not necessarily reflect an important ingredient in the accretion history of terrestrial planets (Johansen et al. 2015), although this cannot be excluded for earlier chondrule precursors with older generations (Zhu et al. 2019a). Considering its very old age and the short half-life of 0.7 Ma of 26Al, the heat source for melting of the EC 002 parent body must have been the decay of 26Al. The reason why EC 002 cooled and crystallized so early might have been that its parent body was of a much smaller size than the terrestrial planets, since small bodies cannot retain their heat well. The size of the EC 002 parent body may have been smaller than the size of asteroids like Vesta (with mean radius of 262.7 km; Russell et al. 2012) and the angrite and aubrite (main-group) parent bodies, which differentiated later, at 2.5–5 Ma after CAIs (Amelin 2008a; Trinquier et al. 2008; Zhu et al. 2019b, 2021b).
Citation: Koefoed et al. 2016
Citation function: Compare/Contrast; Compare/Contrast
While these S/Ns may not look promising, there is an interesting question that one can ask: How much LUVOIR-15 m time is needed to detect the present Earth-level concentration of NO2 around a Sun-like star at 10 pc? Figure 6(a) shows the spectrum of the difference in geometric albedo with and without NO2. Also shown as dashed lines are the noise levels for 10 (blue), 300 (red), and 1200 (black) hr of LUVOIR-A observation times. The present Earth level of NO2 seems to be well above the noise level after 300 hr of observation time (compare the solid green curve with dashed red line), indicating that it might be detectable. To find out with what S/N it would be detectable, Figure 6(b) shows the “net S/N” to detect present Earth-level NO2 as a function of observation time. To achieve a net S/N of 5 (dashed red line), it would take LUVOIR-15 m about 400 hr. For comparison, to obtain the Hubble Ultra Deep Field (UDF) image, ∼400 hr of actual observation time (∼1 yr in real time) was needed (Beckwith et al. 2006). In fact, Hubble has run even larger programs, such as the CANDLES galaxy evolution survey (Grogin et al. 2011) with 902 orbits (∼900 hr of observation time assuming ∼1 hr per orbit). This took about 3 yr in real time. However, these large programs also obtained data on a huge sample size with thousands of galaxies. LUVOIR is envisaged to be 100% community-competed time, and the final report of the LUVOIR team laid out a Design Reference Mission (DRM) in which comparable allocations of time were spent on general astrophysics observations and exoplanet detection and characterization observations during the first 5 yr of the mission. So, over the course of the nominal LUVOIR mission lifetime of about 5 yr, it may be possible to take data with ∼400 hr observation time on a prime HZ planet candidate(s) within 10 pc, to potentially obtain an S/N ∼ 5 for an NO2 feature at the present Earth level on an Earth–Sun system at 10 pc. An even more interesting aspect is that we can place upper limits on the amount of NO2 available on that planet as we spend more observation time on a prime HZ candidate. This could potentially indicate the presence or absence or the level of technological civilization on that planet.
Citation: Beckwith et al. 2006
Citation function: Background
Some studies use HIPPARCOS or Gaia data to determine the evolutionary status of field LiRG and show that these objects tend to accumulate close to the RGB bump, the clump, and the early-AGB (e.g. Charbonnel & Balachandran 2000; Kumar et al. 2011; Smiljanic et al. 2018; Deepak 2019), which is in agreement with open cluster studies (e.g. Delgado Mena et al. 2016). Other works report, however, that LiRG can be randomly located in the HRD (Jasniewicz et al. 1999; Smith et al. 1999; Monaco et al. 2011; Lebzelter et al. 2012; Martell & Shetrone 2013; Casey et al. 2016). The distinction is crucial to understanding the processes that may provide an explanation for the phenomenon, such as fresh Li production by internal mixing processes (Sackmann & Boothroyd 1999; Palacios et al. 2001; Guandalini et al. 2009; Strassmeier et al. 2015; Cassisi et al. 2016), prompt mass loss events (de La Reza et al. 1996, 1997), Li accretion during engulfment of planets or planetesimals (Alexander 1967; Siess & Livio 1999; Carlberg et al. 2010; Aguilera-Gómez et al. 2016a,b; Delgado Mena et al. 2016), tidal interactions between binary stars (Casey et al. 2019), or a combination of these mechanisms (Denissenkov & Weiss 2000; Denissenkov & Herwig 2004). However, since the evolution tracks of evolved stars all converge to the same area of the CMD, the definitive determination of the actual evolution status of LiRG requires asteroseismology to probe their internal structure and disentangle RGB from clump stars. As of today, very few LiRG have been observed with CoRoT and Kepler. The majority seems to be located in the core-He burning clump (Silva Aguirre et al. 2014; Bharat Kumar et al. 2018; Casey et al. 2016; Smiljanic et al. 2018; Singh et al. 2019), with the others being at the RGB bump or higher on the first ascent giant branch (Jofré et al. 2015; Casey et al. 2019). In a recent study using LAMOST spectra to derive both the Li abundance and asteroseismic classification, Casey et al. (2019) showed that ∼80% of their large sample of low-mass LiRG (2330 objects) probably have helium burning cores. They find that LiRG are more frequent at higher metallicity.
Citation: Martell & Shetrone 2013
Citation function: Differences; Motivation
In addition to thermal excitation through collisions with H2 and He, absorption of infrared photons and pumping to excited vibrational states, followed by radiative decay to rotational levels in the ground-vibrational state, is an important excitation mechanism of molecules in IRC +10216 (Deguchi & Uyemura 1984; Agúndez & Cernicharo 2006; González-Alfonso et al. 2007; Agúndez et al. 2008, 2015; Cordiner & Millar 2009; Daniel et al. 2012; De Beck et al. 2012). Here, we have included excitation through infrared pumping for all studied species, mostly through bands lying in the mid-infrared, where the flux in IRC +10216 is large (Cernicharo et al. 1999). To facilitate the excitation and radiative transfer calculations, we have collapsed the fine rotational structure of the radicals and simply treated these species as linear molecules with a 1Σ electronic state. For C2H, we have included the first four vibrationally excited states of the bending mode (ν2 = 1, 2, 3, 4), and the first vibrationally excited states of the stretching modes (ν1 = 1 and ν3 = 1). The vibrationally excited state that plays the most important role, through infrared pumping, in the excitation of C2H in IRC +10216 is ν2 = 1, which lies 371 cm-1 above the ground-vibrational state. The wavelengths and strengths of the vibrational bands have been taken from Tarroni & Carter (2004). For the radical CN, we have included the v = 0 → 1 band, lying at 2042 cm-1 (Hübner et al. 2005; Brooke et al. 2014), which plays a minor role on the excitation of the λ 3 mm lines in IRC +10216, however. For HC3N, we have included the first excited states of the vibrational bending modes ν5 and ν6, which have strong fundamental bands at 663 and 498 cm-1. The wavelengths and strengths of the vibrational bands are from the compilation by J. Crovisier1, which are based on extensive laboratory work (e.g., Uyemura et al. 1982; Jolly et al. 2007). For cyanodiacetylene, we have included the first excited states of the vibrational bending modes ν7 and ν8, whose calculated fundamental bands, lying at 566 and 685 cm-1, have been found to be important for the rotational excitation of HC5N in IRC +10216 (Deguchi & Uyemura 1984). For the radicals C4H, C6H, and C3N there is little information on the wavelengths and strengths of vibrational bands. For these species we have instead included a generic vibrationally excited state lying at 15 μm above the ground-vibrational state, with an Einstein coefficient of spontaneous emission of 5 s-1 for the P(1) transition of the vibrational band. A similar treatment, with slightly different parameters, was adopted for C4H and C6H by Cordiner & Millar (2009).
Citation: Cernicharo et al. 1999
Citation function: Uses
In a similar fashion to what done by the CARLA survey, the COBRA (Clusters Occupied by Bent Radio AGN) program (Paterno-Mahler et al. 2017) searches for overdense regions around radio-AGN with double-lobed structures which are not aligned with each other, but bent by forming angles 180∘\documentclass[12pt]{minimal}
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				\begin{document}$$180^\circ$$\end{document}. The rationale behind this search is that the radio lobes of these AGNs are most likely bent because of the ram pressure that occurs due to the relative motion of the AGN host galaxy and the ICM (e.g., Feretti et al. 1992; Blanton et al. 2001; Giacintutti and Venturi 2009; Wing and Blanton 2011), which makes these sources good tracers for finding galaxy clusters. Indeed, out of 646 bent radio-AGN, 530 (corresponding to ∼\documentclass[12pt]{minimal}
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				\begin{document}$$\sim$$\end{document} 82% of the original sample) are associated with over-densities—mostly at high, z=1-3\documentclass[12pt]{minimal}
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				\begin{document}$$z=1-3$$\end{document}, redshifts—in the Spitzer/IRAC maps, and 190 are associated with galaxy cluster candidates. By following up on the previous work, Golden-Marx et al. (2021) also show for a subsample of 36 high-z (0.35z2.2\documentclass[12pt]{minimal}
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				\begin{document}$$0.35z2.2$$\end{document}) cluster candidates that radio-AGN with narrower (≲80∘\documentclass[12pt]{minimal}
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				\begin{document}$$\lesssim 80^\circ$$\end{document}) opening angles reside in richer clusters (cf. Fig. 26), clearly indicating that the cluster environment impacts radio morphology.
Citation: Blanton et al. 2001
Citation function: Motivation; Motivation