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Related papers: Stellar evolution in the outer Galaxy

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Recent studies have identified several young stellar objects (YSOs) which exhibit significant mid-infrared (mid-IR) variability. A wide range of physical mechanisms may be responsible for these variations, including changes in a YSO's…

The mid-infrared provides a unique view of galaxy stellar populations, sensitive to both the integrated light of old, low-mass stars and to individual dusty mass-losing stars. We present results from an extended Spitzer/IRAC survey of M31…

Astrophysics of Galaxies · Physics 2017-03-29 P. Barmby , M. Rafiei Ravandi

We report new Spitzer Space Telescope observations from the IRAC and MIPS instruments of the young (~ 3 Myr) sigma Orionis cluster. We identify 336 stars as members of the cluster using optical and near-infrared color magnitude diagrams.…

We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (-1.4 deg $\lesssim l \lesssim$ -0.3 deg and 1.0 deg $\lesssim l \lesssim$ 2.9 deg, $|b|\lesssim$ 0.1 deg), using the…

Astrophysics of Galaxies · Physics 2015-06-19 Tatsuhito Yoshikawa , Shogo Nishiyama , Motohide Tamura , Jungmi Kwon , Tetsuya Nagata

The comparison between the new Spitzer data at 24 micron and the previous ISOCAM data at 15 micron is a key tool to understand galaxy properties and evolution in the infrared and to interpret the observed number counts, since the…

Astrophysics · Physics 2009-11-10 C. Gruppioni , F. Pozzi , C. Lari , S. Oliver , G. Rodighiero

We present new images and photometry of the massive star forming complex Cygnus X obtained with IRAC and MIPS on the Spitzer Space Telescope. A combination of IRAC, MIPS, UKIDSS, and 2MASS data are used to identify and classify young…

A proper analysis of the evolution of sources emitting in the Mid-Infrared is strongly dependent on their broad-band spectral properties (SEDs) at different redshifts and luminosities and on a reliable classification allowing to disentangle…

Astrophysics · Physics 2007-05-23 C. Gruppioni , F. Pozzi , A. Comastri , C. Vignali , G. Rodighiero , .

We investigated the distributions of classified young stellar object (YSO) in nine star-forming regions associated with Hii regions, namely Sh2-22, Sh2-19, Sh2-17, M16, M8, IC5070, Sh2-252, NGC2467 and M42, as a means of exploring the star…

Astrophysics of Galaxies · Physics 2025-11-13 Annarien G. Headley , James O. Chibueze

We have used GALEX and SDSS observations to extract 7 band photometric magnitudes for over 80,000 objects in the vicinity of the North Galactic Pole. Although these had been identified as stars by the SDSS pipeline, we found through fitting…

Astrophysics of Galaxies · Physics 2013-11-13 K. Preethi , S. B. Gudennavar , S. G. Bubbly , Jayant Murthy , Noah Brosch

Classification of young stellar objects (YSOs) into different evolutionary stages helps us to understand the formation process of new stars and planetary systems. Such classification has traditionally been based on spectral energy…

Astrophysics of Galaxies · Physics 2018-09-05 Oskari Miettinen

We present 0.5 -160 micron Spectral Energy Distributions (SEDs) of galaxies, detected at 70microns with the Multiband Imaging Photometer for Spitzer (MIPS), using broadband imaging data from Spitzer and ground-based telescopes.…

We present initial results from a population synthesis model aimed at determining the star formation rate of the Milky-Way. We find that a total star formation rate of 0.68 to 1.45 Msun/yr is able to reproduce the observed number of young…

Astrophysics of Galaxies · Physics 2010-01-22 Thomas P. Robitaille , Barbara A. Whitney

The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (3.6 & 4.5 um) time-series photometry of the Orion Nebula Cluster plus smaller footprints in eleven other…

We present a spectroscopic follow-up of photometrically-selected young stellar object (YSO) candidates in the Central Molecular Zone of the Galactic center. Our goal is to quantify the contamination of this YSO sample by reddened giant…

Galaxies selected at 170um by the ISO FIRBACK survey represent the brightest \~10% of the Cosmic Infrared Background. Examining their nature in detail is therefore crucial for constraining models of galaxy evolution. Here we combine Spitzer…

Astrophysics · Physics 2009-11-11 A. Sajina , D. Scott , M. Dennefeld , H. Dole , M. Lacy , G. Lagache

We have selected red MSX sources (RMS) that have the colours of massive young stellar objects (MYSOs). Our aim is to generate a large, systematically selected sample to address questions such as their luminosity function, lifetimes,…

Astrophysics · Physics 2007-05-23 MG Hoare , SL Lumsden , RD Oudmaijer , AL Busfield , TL King , TLJ Moore

Galaxy source counts that simultaneously fit the deep mid-infrared surveys at 24 microns and 15 microns made by the Spitzer Space Telescope and the Infrared Space Observatory (ISO) respectively are presented for two phenomenological models.…

Astrophysics · Physics 2009-11-10 Chris P. Pearson

The Sloan Digital Sky Survey (SDSS) and Two Micron All Sky Survey (2MASS) are rich resources for studying stellar astrophysics and the structure and formation history of the Galaxy. As new surveys and instruments adopt similar filter sets,…

The outer Galaxy presents a distinctive environment for investigating star formation. This study develops a novel approach to identify true cluster members based on unsupervised clustering using astrometry with significant uncertainties. As…

Astrophysics of Galaxies · Physics 2025-07-15 Vishwas Patel , Joseph L. Hora , Matthew L. N. Ashby , Sarita Vig

Mass loss is a key aspect of stellar evolution, particularly in evolved massive stars, yet episodic mass loss remains poorly understood. To investigate this, we need evolved massive stellar populations across various galactic environments.…