More Like this

1. 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)

   Abstract 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 ${\mathit{}}_{12/13}\equiv I{[}^{12}\mathrm{CO}(J=1\to 0)\left]/I{[}^{13}\mathrm{CO}\right(J=1\to 0\left)\right]$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. 

   more » « less
2. ALMA Observations of Circumnuclear Disks in Early-type Galaxies: ¹² CO(2−1) and Continuum Properties

   https://doi.org/10.3847/1538-4357/aa8266  

   Boizelle, Benjamin D.; Barth, Aaron J.; Darling, Jeremy; Baker, Andrew J.; Buote, David A.; Ho, Luis C.; Walsh, Jonelle L. (August 2017, The Astrophysical Journal)
3. SO and SiS Emission Tracing an Embedded Planet and Compact ¹² CO and ¹³ CO Counterparts in the HD 169142 Disk

   https://doi.org/10.3847/2041-8213/acdfd0  

   Law, Charles J.; Booth, Alice S.; Öberg, Karin I. (August 2023, The Astrophysical Journal Letters)

   Abstract Planets form in dusty, gas-rich disks around young stars, while at the same time, the planet formation process alters the physical and chemical structure of the disk itself. Embedded planets will locally heat the disk and sublimate volatile-rich ices, or in extreme cases, result in shocks that sputter heavy atoms such as Si from dust grains. This should cause chemical asymmetries detectable in molecular gas observations. Using high-angular-resolution ALMA archival data of the HD 169142 disk, we identify compact SOJ= 8₈− 7₇and SiSJ= 19 − 18 emission coincident with the position of a ∼ 2M_Jupplanet seen as a localized, Keplerian NIR feature within a gas-depleted, annular dust gap at ≈38 au. The SiS emission is located along an azimuthal arc and has a morphology similar to that of a known¹²CO kinematic excess. This is the first tentative detection of SiS emission in a protoplanetary disk and suggests that the planet is driving sufficiently strong shocks to produce gas-phase SiS. We also report the discovery of compact¹²CO and¹³COJ= 3 − 2 emission coincident with the planet location. Taken together, a planet-driven outflow provides the best explanation for the properties of the observed chemical asymmetries. We also resolve a bright, azimuthally asymmetric SO ring at ≈24 au. While most of this SO emission originates from ice sublimation, its asymmetric distribution implies azimuthal temperature variations driven by a misaligned inner disk or planet–disk interactions. Overall, the HD 169142 disk shows several distinct chemical signatures related to giant planet formation and presents a powerful template for future searches of planet-related chemical asymmetries in protoplanetary disks. 

   more » « less
4. State-to-state vacuum ultraviolet photodissociation study of CO ₂ on the formation of state-correlated CO(X ¹ Σ ⁺ ; v) with O( ¹ D) and O( ¹ S) photoproducts at 11.95–12.22 eV

   https://doi.org/10.1039/c5cp01321f  

   Lu, Zhou; Chang, Yih Chung; Benitez, Yanice; Luo, Zhihong; Houria, Adel Ben; Ayari, Tarek; Al Mogren, Muneerah Mogren; Hochlaf, M.; Jackson, W. M.; Ng, C. Y. (January 2015, Phys. Chem. Chem. Phys.)
5. Electrochemical Oxidation of [1-X-12-I-CB ₁₁ Me ₁₀ ^– ] Anions: Formation of Borenium Ylides [12-Dehydro-1-X-CB ₁₁ Me ₁₀ ] and Iodonium Ylide Anions [{12-(1-X-CB ₁₁ Me ₁₀ ^– )} ₂ I ⁺ ]

   https://doi.org/10.1021/acs.inorgchem.6b02128  

   Wahab, Abdul; Kaleta, Jiří; Wen, Jin; Valášek, Michal; Polášek, Miroslav; Michl, Josef; Ludvík, Jiří (December 2016, Inorganic Chemistry)