Characterizing the Evolved Stellar Population in the Galactic Foreground I: Bolometric Magnitudes, Spatial Distribution and P-L Relations
Luis Henry Quiroga-Nuñez, Huib Jan van Langevelde, Loránt O. Sjouwerman, Ylva M. Pihlström, Anthony G. A. Brown, R. Michael Rich, Michael C. Stroh, Megan O. Lewis, Harm J. Habing
Radio campaigns using maser stellar beacons have provided crucial information to characterize Galactic stellar populations. Currently, the Bulge Asymmetries and Dynamical Evolution (BAaDE) project is surveying infrared (IR) color-selected targets for SiO masers. This provides a sample of evolved stars that can be used to study the inner, optically obscured Galaxy using line of sight velocities and possibly VLBI proper motions. In order to use the BAaDE sample for kinematic studies, the stellar population should be characterized. In this study, the BAaDE targets have been cross-matched with IR (2MASS) and optical Gaia samples. By exploring the synergies of this cross-match together with Gaia parallaxes and extinction maps, the local ($d < 2$ kpc) AGB stars can be characterized. We have defined a \textit{BAaDE-Gaia} sample of 20,111 sources resulting from cross-matching BAaDE targets with IR and optical surveys. From this sample, a~{\local} sample of 1,812 evolved stars with accurate parallax measurements, confirmed evolved stellar evolution stage, and within 2 kpc distance around the Sun was selected, for which absolute (bolometric) magnitudes are estimated. The evolved stellar population with Gaia counterparts that are variable seems to be predominantly associated with AGB stars with moderate luminosity ($1,500^{+3,000}_{-500} \ L_\odot$) and periods between 250 and 1,250 days.
JWST NIRCam and MIRI Reveal the Dust-Producing AGB Population of NGC 6822
Institute for Astronomy, University of Edinburgh（爱丁堡大学天体物理研究所）；UK Astronomy Technology Centre, Royal Observatory（英国天文技术中心，皇家天文台）；IPAC, California Institute of Technology（加州理工学院IPAC）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Department of Physics & Engineering Physics, Morgan State University（摩根州立大学物理与工程物理系）；Department of Physics, Maynooth University（梅努斯大学物理系）；Space Telescope Science Institute（太空望远镜科学研究所）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；SETI Institute（搜寻地外文明研究所）；Centre for Astrophysics Research, Department of Physics, Astronomy and Mathematics, College Lane Campus, University of Hertfordshire（赫特福德大学College Lane校区物理、天文与数学系天体物理研究中心）
Characterizing the Post-Red Supergiant binary system AFGL 4106 and its complex nebula with SPHERE/VLT
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心、拉格朗日实验室）；Departamento de Física, Universidad de Santiago de Chile（圣地亚哥德智利大学物理系）；Center for Interdisciplinary Research in Astrophysics and Space Exploration (CIRAS), USACH（天体物理学与太空探索跨学科研究中心（CIRAS））；Royal Observatory of Belgium（比利时皇家天文台）；School of Physics & Astronomy, University of Leeds（利兹大学物理与天文学学院）
Diameters and Temperatures VII: High-angular resolution measurements of Solar-type stars with the CHARA Array
Louisiana State University（路易斯安那州立大学）；Lowell Observatory（洛厄尔天文台）；Georgia State University（佐治亚州立大学）；University of Sydney（悉尼大学）；University of Hawaii（夏威夷大学）；Australian National University（澳大利亚国立大学）；University of Rochester（罗切斯特大学）
The UK Infrared Telescope M33 monitoring project. III. Feedback from dusty stellar winds in the central square kiloparsec
我们已经在英国天文台红望远镜（UKIRT）对本星系群螺旋星系M33（三角座）进行了近红外监测活动。其主要目的是识别处于演化最后阶段的恒星，这些恒星的光度与其诞生质量的关系比数量更多但光度持续增加的低演化巨星更直接。在本系列的第三篇论文中，我们测量了脉动渐近巨星分支（AGB）恒星和红超巨星的尘埃产生和质量损失率。为此，我们结合了我们的时间平均近红外测光与多历元中红外测光获得斯皮策太空望远镜。质量损失率被认为是增加与脉动的强度增加，并与增加测热光度。低质量恒星通过星风失去大部分质量，但即使是超AGB星和红超巨星也会通过尘埃星风失去$\sim40$ %的质量。超过四分之三的粉尘返回是含氧的。我们构建了一个质量返回率的2-D地图，显示了径向下降，但也局部增强由于大质量恒星的聚集。我们估计总质量损失率为0.004- 0.005 M $_\odot$ yr $^{-1}$ kpc $^{-2}$，当考虑喷发质量损失时，增加到$\sim0.006$ M $_\odot$ yr $^{-1}$ kpc $^{-2}$（例如，超新星）;将此与当前的恒星形成速率$\sim0.03$ M $_\odot$ yr $^{-1}$ kpc $^{-2}$进行比较，我们得出结论，只有当气体从盘的更远处或从环银河系区域吸积时，M 1，33中心区域的恒星形成才能持续。
