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We present the first non-LTE, co-moving frame molecular line calculations of a star-forming cluster simulated using smoothed particle hydrodynamics (SPH), from which we derive high-resolution synthetic observations. We have resampled a…

Solar and Stellar Astrophysics · Physics 2015-05-18 David Rundle , Tim J. Harries , David M. Acreman , Matthew R. Bate

Inferring stellar parameters and chemical abundances by forward modeling stellar spectra usually requires a spectral synthesis code, or an emulator constructed from a curated training set. In these situations continuum normalization is…

Solar and Stellar Astrophysics · Physics 2026-01-29 Andrew R. Casey , Adam Wheeler , Megan Bedell , David W. Hogg , Andrew Sayjdari , Lily Zhao

An analysis of the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey has produced a sample of 27 candidate dense molecular clumps with large collapse motions, as revealed by large ``blue'' asymmetrical line profiles of the optically…

The detection of GW170817 and the accompanying electromagnetic counterpart, AT2017gfo, have provided an important set of observational constraints for theoretical models of neutron star mergers, nucleosynthesis, and radiative transfer for…

On-going measurements of the cosmic radiation (nuclear, electronic, and gamma-ray) are shedding new light on cosmic-ray physics. A comprehensive picture of these data relies on an accurate determination of the transport and source…

High Energy Astrophysical Phenomena · Physics 2010-07-08 A. Putze , L. Derome , D. Maurin

N2H+ observations of molecular cloud cores in Taurus with the Nobeyama 45 m radio telescope are reported. We compare ``cores with young stars'' with ``cores without young stars''. The differences in core radius, linewidth, and core mass are…

Astrophysics · Physics 2009-11-10 K. Tatematsu , T. Umemoto , R. Kandori , Y. Sekimoto

Low-mass stars like our Sun begin their evolution within cold (10 K) and dense ($\sim 10^5$ cm$^{-3}$) cores of gas and dust. The physical structure of starless cores is best probed by thermal emission of dust grains. We present a high…

Astrophysics of Galaxies · Physics 2023-04-05 Samantha Scibelli , Yancy Shirley , Anika Schmiedeke , Brian Svoboda , Ayushi Singh , James Lilly , Paola Caselli

This analysis begins to explore the complex chromosphere-corona mass cycle using a blend of imaging and spectroscopic diagnostics. Single Gaussian fits to hot emission line profiles (formed above 1MK) at the base of coronal loop structures…

Solar and Stellar Astrophysics · Physics 2015-06-04 Scott W. McIntosh , Hui Tian , Marybeth Sechler , Bart De Pontieu

We investigate the Lyman alpha line transfer in nearby and high redshift starbursting galaxies, where the effect of high optical depths and the role of dust in the scattering medium are expected to be conspicuous and should be treated in a…

Astrophysics · Physics 2009-10-31 Sang-Hyeon Ahn , Hee-Won Lee , Hyung Mok Lee

Physical and chemical conditions (kinetic temperature, volume density, molecular composition) of interstellar clouds are inherent in their mm-submm line spectra, making spectral line profiles powerful diagnostics of source conditions. We…

Context: Knowledge about hot, massive stars is usually inferred from quantitative spectroscopy. To analyse non-spherical phenomena, the existing 1D codes must be extended to higher dimensions, and corresponding tools need to be developed.…

Solar and Stellar Astrophysics · Physics 2019-12-25 L. Hennicker , J. Puls , N. D. Kee , J. O. Sundqvist

We present newly processed archival Herschel images of molecular cloud MCLD 123.5+24.9 in the Polaris Flare. This cloud contains five starless cores. Using the spectral synthesis code Cloudy, we explore uncertainties in the derivation of…

Astrophysics of Galaxies · Physics 2015-08-10 Gururaj A. Wagle , Thomas H. Troland , Gary J. Ferland , Nicholas P. Abel

We apply photo-dissociation region (PDR) molecular line emission models, that have varying degrees of enhanced mechanical heating rates, to the gaseous component of simulations of star-forming galaxies taken from the literature. Snapshots…

Astrophysics of Galaxies · Physics 2016-11-23 M. V. Kazandjian , I. Pelupessy , R. Meijerink , F. P. Israel , M. Spaans

We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire…

Astrophysics · Physics 2009-10-31 C. D. Wilson , J. E. Howe , M. L. Balogh

We present Atacama Large Millimeter Array (ALMA) Cycle-0 observations of the CO J = 6-5 line in the advanced galaxy merger Arp 220. This line traces warm molecular gas, which dominates the total CO luminosity. The CO emission from the two…

Astrophysics of Galaxies · Physics 2015-06-11 Naseem Rangwala , Philip Maloney , Christine Wilson , Jason Glenn , Julia Kamenetzky , Luigi Spinoglio

For many transitions, atomic data, such as the oscillator strength (log(gf)) and the central wavelength of the line, are poorly constrained or even unknown. We present and test a new inversion method that infers atomic line parameters and…

Solar and Stellar Astrophysics · Physics 2024-06-19 D. Vukadinović , H. N. Smitha , A. Korpi-Lagg , M. van Noort , J. S. Castellanos Durán , S. K. Solanki

We have mapped the starless core TMC-1C in a variety of molecular lines with the IRAM 30m telescope. High density tracers show clear signs of self-absorption and sub-sonic infall asymmetries are present in N2H+ (1-0) and DCO+ (2-1) lines.…

Astrophysics · Physics 2009-11-13 S. Schnee , P. Caselli , A. Goodman , H. G. Arce , J. Ballesteros-Paredes , K. Kuchibhotla

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

Astrophysics of Galaxies · Physics 2015-06-16 Paul F. Goldsmith

We analyze a three-dimensional smoothed particle hydrodynamics simulation of an evolving and later collapsing pre-stellar core. Using a three-dimensional continuum radiative transfer program, we generate images at 7 micron, 15 micron, 175…

Astrophysics · Physics 2009-11-10 J. Steinacker , B. Lang , A. Burkert , A. Bacmann , Th. Henning