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Related papers: Comparing simulated $^{26}$Al maps to gamma-ray me…

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Al(26) radioactivity traces recent nucleosynthesis throughout the Galaxy, and is known to be produced in massive stars and novae. The map from its decay gamma-ray line suggests massive stars to dominate, but high-resolution line…

In a previous paper, we calculated numerical hydrodynamic models of the interstellar medium in the Galaxy, which suggested that hot gas (T $\ge$ 3 $\times$ 10$^5$ K) has a filling factor near 50\% in the midplane (Rosen \& Bregman 1995, ApJ…

Astrophysics · Physics 2009-10-28 Alexander Rosen , Joel N. Bregman , Daniel D. Kelson

Radioactive 26Al is an excellent tracer for metal ejection in the Milky Way, and can provide a direct constraint on the modelling of supernova feedback in galaxy evolution. Gamma-ray observations of the 26Al decay line have found high…

Astrophysics of Galaxies · Physics 2020-12-02 Martin G. H. Krause , Donna Rodgers-Lee , James E. Dale , Roland Diehl , Chiaki Kobayashi

We use hydrodynamical simulations to study the Milky Way's central molecular zone (CMZ). The simulations include a non-equilibrium chemical network, the gas self-gravity, star formation and supernova feedback. We resolve the structure of…

The Milky Way's galactic center is a highly dynamical, crowded environment. Gamma ray observations of this region, such as the excess of GeV scale gamma rays observed by Fermi LAT, have been of tremendous interest to both the high energy…

High Energy Astrophysical Phenomena · Physics 2025-09-24 Isabel S. Sands , Philip F. Hopkins , Sam B. Ponnada , Dusan Keres , Lina Necib , Yen-Hsing Julius Lin

Gamma-ray telescopes are capable of measuring radioactive trace isotopes from cosmic nucleosynthesis events. Such measurements address new isotope production rather directly for a few key isotopes such as 44Ti, 26Al, 60Fe, and 56Ni, as well…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Roland Diehl

Gamma-ray line emission from radioactive decay of 60Fe provides constraints on nucleosynthesis in massive stars and supernovae. The spectrometer SPI on board INTEGRAL has accumulated nearly three years of data on gamma-ray emission from the…

Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of NHI ~ 10^19 cm-2, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Attila Popping , Romeel Dave , Robert Braun , Benjamin D. Oppenheimer

It has been recently found that the local fluctuations of the QSO's Ly$\alpha$ absorption spectrum transmitted flux show spiky structures. This implies that the mass fields of the intergalactic medium (IGM) is intermittent. This feature…

Astrophysics · Physics 2008-11-26 Long-Long Feng , Jesus Pando , Li-Zhi Fang

We introduce a new set of eight Milky Way-sized cosmological simulations performed using the AMR code ART + Hydrodynamics in a LCDM cosmology. The set of zoom-in simulations covers present-day virial masses in the 0.83-1.56 x 10^12 msun…

Astrophysics of Galaxies · Physics 2016-10-05 Pedro Colin , Vladimir Avila-Reese , Santi Roca-Fabrega , Octavio Valenzuela

We use a cosmological hydrodynamic simulation calculated with Enzo and the semi-analytic galaxy formation model (SAM) GAMMA to address the chemical evolution of dwarf galaxies in the early universe. The long-term goal of the project is to…

Astrophysics of Galaxies · Physics 2018-06-06 Benoit Côté , Devin Silvia , Brian W. O'Shea , Britton Smith , John H. Wise

Galaxy groups are more than an intermediate scale between clusters and halos hosting individual galaxies, they are crucial laboratories capable of testing a range of astrophysics from how galaxies form and evolve to large scale structure…

Astrophysics of Galaxies · Physics 2021-06-28 Benjamin D. Oppenheimer , Arif Babul , Yannick Bahé , Iryna S. Butsky , Ian G. McCarthy

COMPTEL imaging analysis revealed a patchy, asymmetric distribution of diffuse 1.8 MeV emission along the Galactic plane, which is attributed to the decay of radioactive 26Al in the ISM. If massive stars were the major source of Galactic…

Gamma-rays from the decay of $^{26}$Al offer a stringent constraint on the Galaxy's global star formation rate over the past million years, supplementing other methods for quantifying the recent Galactic star formation rate, such as…

Astrophysics · Physics 2009-10-30 F. X. Timmes , R. Diehl , D. H. Hartmann

The Astro2020 Decadal Survey has identified the mapping of the circumgalactic medium (CGM, gaseous plasma around galaxies) as a key objective. We explore the prospects for characterizing the CGM in and around nearby galaxy halos with a…

The distribution of diffuse gas in the intergalactic medium (IGM) imprints a series of hydrogen absorption lines on the spectra of distant background quasars known as the Lyman-$\alpha$ forest. Cosmological hydrodynamical simulations…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Alberto Rorai , Joseph F. Hennawi , Jose Oñorbe , Martin White , J. Xavier Prochaska , Girish Kulkarni , Michael Walther , Zarija Lukić , Khee-Gan Lee

Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane…

Studies based on the gamma-ray lines from radioactive decay of unstable isotopes produced in massive-star and supernova nucleosynthesis have been among INTEGRAL's prominent science achievements. 26Al has become a tool to study specific…

High Energy Astrophysical Phenomena · Physics 2013-07-17 Roland Diehl , Frauke Alexander , Martin Krause , Daniel Lubos , Karsten Kretschmer , Pierrick Martin , Wei Wang

Diffuse gamma-ray emission is a key tracer of cosmic rays (CRs) in galaxies, encoding information about their transport, energetics, and interactions with the interstellar medium. Interpreting the Milky Way gamma-ray sky is challenging…

Using hydrodynamical simulations of entire galactic discs similar to the Milky Way, reaching 4.6pc resolution, we study the origins of observed physical properties of giant molecular clouds (GMCs). We find that efficient stellar feedback is…

Astrophysics of Galaxies · Physics 2018-07-04 Kearn Grisdale , Oscar Agertz , Florent Renaud , Alessandro B. Romeo