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1. What Does the Geometry of the Hβ BLR Depend On?

   https://doi.org/10.3847/1538-4357/accc84  

   Villafaña, Lizvette ; Williams, Peter R. ; Treu, Tommaso ; Brewer, Brendon J. ; Barth, Aaron J. ; U, Vivian ; Bennert, Vardha N. ; Guo, Hengxiao ; Bentz, Misty C. ; Canalizo, Gabriela ; et al ( May 2023 , The Astrophysical Journal)

   We combine our dynamical modeling black-hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors,f, used in traditional reverberation-mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have utilized our methods. Aiming to improve the precision of black-hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations betweenfand other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient${\log }_{10}(f_{\mathrm{mean},\sigma })$and black-hole mass, (ii) marginal evidence for a similar correlation between${\log }_{10}(f_{\mathrm{rms},\sigma })$and black-hole mass, (iii) marginal evidence for an anticorrelation of BLR disk thickness with${\log }_{10}(f_{\mathrm{mean},\mathrm{FWHM}})$and${\log }_{10}(f_{\mathrm{rms},\mathrm{FWHM}})$, and (iv) marginal evidence for an anticorrelation of inclination angle with${\log }_{10}(f_{\mathrm{mean},\mathrm{FWHM}})$,${\log }_{10}(f_{\mathrm{rms},\sigma })$, and${\log }_{10}(f_{\mathrm{mean},\sigma })$. Last, we find marginal evidence for a correlation between line-profile shape, when using the root-mean-square spectrum,${\log }_{10}{(\mathrm{FWHM}/\sigma )}_{\mathrm{rms}}$, and the virial coefficient,${\log }_{10}(f_{\mathrm{rms},\sigma })$, and investigate how BLR properties might be related to line-profile shape usingcaramelmodels.

    

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2. Characterizing the fundamental bending vibration of a linear polyatomic molecule for symmetry violation searches

   https://doi.org/10.1088/1367-2630/ace471  

   Jadbabaie, Arian ; Takahashi, Yuiki ; Pilgram, Nickolas H ; Conn, Chandler J ; Zeng, Yi ; Zhang, Chi ; Hutzler, Nicholas R ( July 2023 , New Journal of Physics)

   Polyatomic molecules have been identified as sensitive probes of charge-parity violating and parity violating physics beyond the Standard Model (BSM). For example, many linear triatomic molecules are both laser-coolable and have parity doublets in the ground electronic$\tilde{X}{}^2{\mathrm{\Sigma }}^{+}(010)$state arising from the bending vibration, both features that can greatly aid BSM searches. Understanding the$\tilde{X}{}^2{\mathrm{\Sigma }}^{+}(010)$state is a crucial prerequisite to precision measurements with linear polyatomic molecules. Here, we characterize the fundamental bending vibration of${}^{174}$YbOH using high-resolution optical spectroscopy on the nominally forbidden$\tilde{X}{}^2{\mathrm{\Sigma }}^{+}(010)$$\to \tilde{A}{}^2{\mathrm{\Pi }}_{1/2}(000)$transition at 588 nm. We assign 39 transitions originating from the lowest rotational levels of the$\tilde{X}{}^2{\mathrm{\Sigma }}^{+}(010)$state, and accurately model the state’s structure with an effective Hamiltonian using best-fit parameters. Additionally, we perform Stark and Zeeman spectroscopy on the$\tilde{X}{}^2{\mathrm{\Sigma }}^{+}(010)$state and fit the molecule-frame dipole moment to$D_{\mathrm{m}\mathrm{o}\mathrm{l}}=2.16(1)$Dand the effective electrong-factor to$g_S=2.07(2)$. Further, we use an empirical model to explain observed anomalous line intensities in terms of interference from spin–orbit and vibronic perturbations in the excited$\tilde{A}{}^2{\mathrm{\Pi }}_{1/2}(000)$state. Our work is an essential step toward searches for BSM physics in YbOH and other linear polyatomic molecules.

    

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3. The EDGE-CALIFA Survey: Spatially Resolved 13 CO(1–0) Observations and Variations in 12 CO(1–0)/ 13 CO(1–0) in Nearby Galaxies on Kiloparsec Scales

   https://doi.org/10.3847/1538-4365/acd840  

   Cao, Yixian ; Wong, Tony ; Bolatto, Alberto D. ; Leroy, Adam K. ; Rosolowsky, Erik ; Utomo, Dyas ; Sánchez, Sebastián F. ; Barrera-Ballesteros, Jorge K. ; Levy, Rebecca C. ; Colombo, Dario ; et al ( August 2023 , The Astrophysical Journal Supplement Series)

   We present¹³CO(J= 1 → 0) observations for the EDGE-CALIFA survey, which is a mapping survey of 126 nearby galaxies at a typical spatial resolution of 1.5 kpc. Using detected¹²CO emission as a prior, we detect¹³CO in 41 galaxies via integrated line flux over the entire galaxy and in 30 galaxies via integrated line intensity in resolved synthesized beams. Incorporating our CO observations and optical IFU spectroscopy, we perform a systematic comparison between the line ratio${\mathit{}}_{12/13}\equiv I{[}^{12}\mathrm{CO}(J=1\to 0)]/I{[}^{13}\mathrm{CO}(J=1\to 0)]$and the properties of the stars and ionized gas. Higher${\mathit{}}_{12/13}$values are found in interacting galaxies compared to those in noninteracting galaxies. The global${\mathit{}}_{12/13}$slightly increases with infrared colorF₆₀/F₁₀₀but appears insensitive to other host-galaxy properties such as morphology, stellar mass, or galaxy size. We also present azimuthally averaged${\mathit{}}_{12/13}$profiles for our sample up to a galactocentric radius of 0.4r₂₅(∼6 kpc), taking into account the¹³CO nondetections by spectral stacking. The radial profiles of${\mathit{}}_{12/13}$are quite flat across our sample. Within galactocentric distances of 0.2r₂₅, the azimuthally averaged${\mathit{}}_{12/13}$increases with the star formation rate. However, Spearman rank correlation tests show the azimuthally averaged${\mathit{}}_{12/13}$does not strongly correlate with any other gas or stellar properties in general, especially beyond 0.2r₂₅from the galaxy centers. Our findings suggest that in the complex environments in galaxy disks,${\mathit{}}_{12/13}$is not a sensitive tracer for ISM properties. Dynamical disturbances, like galaxy interactions or the presence of a bar, also have an overall impact on${\mathit{}}_{12/13}$, which further complicates the interpretations of${\mathit{}}_{12/13}$variations.

    

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4. High-harmonic generation in spin and charge current pumping at ferromagnetic or antiferromagnetic resonance in the presence of spin–orbit coupling

   https://doi.org/10.1088/2515-7639/aceaad  

   Varela-Manjarres, Jalil ; Nikolić, Branislav K. ( August 2023 , Journal of Physics: Materials)

   One of the cornerstone effects in spintronics is spin pumping by dynamical magnetization that is steadily precessing (around, for example, thez-axis) with frequencyω₀due to absorption of low-power microwaves of frequencyω₀under the resonance conditions and in the absence of any applied bias voltage. The two-decades-old ‘standard model’ of this effect, based on the scattering theory of adiabatic quantum pumping, predicts that component$I^{S_z}$of spin current vector$(I^{S_x}(t),I^{S_y}(t),I^{S_z})\propto {\omega }_0$is time-independent while$I^{S_x}(t)$and$I^{S_y}(t)$oscillate harmonically in time with a single frequencyω₀whereas pumped charge current is zero$I\equiv 0$in the same adiabatic$\propto {\omega }_0$limit. Here we employ more general approaches than the ‘standard model’, namely the time-dependent nonequilibrium Green’s function (NEGF) and the Floquet NEGF, to predict unforeseen features of spin pumping: namely precessing localized magnetic moments within a ferromagnetic metal (FM) or antiferromagnetic metal (AFM), whose conduction electrons are exposed to spin–orbit coupling (SOC) of either intrinsic or proximity origin, will pump both spin$I^{S_{\alpha }}(t)$and chargeI(t) currents. All four of these functions harmonically oscillate in time at both even and odd integer multiples$N{\omega }_0$of the driving frequencyω₀. The cutoff order of such high harmonics increases with SOC strength, reaching$N_{\mathrm{m}\mathrm{a}\mathrm{x}}\simeq 11$in the one-dimensional FM or AFM models chosen for demonstration. A higher cutoff$N_{\mathrm{m}\mathrm{a}\mathrm{x}}\simeq 25$can be achieved in realistic two-dimensional (2D) FM models defined on a honeycomb lattice, and we provide a prescription of how to realize them using 2D magnets and their heterostructures.

    

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5. Acceleration and Spectral Redistribution of Cosmic Rays in Radio-jet Shear Flows

   https://doi.org/10.3847/1538-4357/acfda9  

   Webb, G. M. ; Xu, Y. ; Biermann, P. L. ; Al-Nussirat, S. ; Mostafavi, P. ; Li, G. ; Barghouty, A. F. ; Zank, G. P. ( November 2023 , The Astrophysical Journal)

   A steady-state, semi-analytical model of energetic particle acceleration in radio-jet shear flows due to cosmic-ray viscosity obtained by Webb et al. is generalized to take into account more general cosmic-ray boundary spectra. This involves solving a mixed Dirichlet–Von Neumann boundary value problem at the edge of the jet. The energetic particle distribution functionf₀(r,p) at cylindrical radiusrfrom the jet axis (assumed to lie along thez-axis) is given by convolving the particle momentum spectrum$f_0(\infty ,p\prime )$with the Green’s function$G(r,p;p\prime )$, which describes the monoenergetic spectrum solution in which$f_0\to \delta (p-p\prime )$asr→ ∞ . Previous work by Webb et al. studied only the Green’s function solution for$G(r,p;p\prime )$. In this paper, we explore for the first time, solutions for more general and realistic forms for$f_0(\infty ,p\prime )$. The flow velocityu=u(r)e_zis along the axis of the jet (thez-axis).uis independent ofz, andu(r) is a monotonic decreasing function ofr. The scattering time$\tau {(r,p)={\tau }_0(p/p_0)}^{\alpha }$in the shear flow region 0 <r<r₂, and$\tau {(r,p)={\tau }_0(p/p_0)}^{\alpha }{(r/r_2)}^s$, wheres> 0 in the regionr>r₂is outside the jet. Other original aspects of the analysis are (i) the use of cosmic ray flow lines in (r,p) space to clarify the particle spatial transport and momentum changes and (ii) the determination of the probability distribution${\psi }_p(r,p;p\prime )$that particles observed at (r,p) originated fromr→ ∞ with momentum$p\prime$. The acceleration of ultrahigh-energy cosmic rays in active galactic nuclei jet sources is discussed. Leaky box models for electron acceleration are described.

    

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