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Related papers: The Galactic center interstellar medium as seen by…

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In this paper we use a number of observations to construct an integrated picture of the ionisation in the interiors of quiescent warm opaque interstellar clouds and in the intercloud medium (ICM) outside dense HII regions and hot dilute…

Astrophysics · Physics 2009-10-30 D. W. Sciama

The mini-spiral is a feature of the interstellar medium in the central ~2 pc of the Galactic center. It is composed of several streamers of dust and ionised and atomic gas with temperatures between a few 100 K to 10^4 K. There is evidence…

We analyse the far infrared dust emission from the Galactic Centre region, including the Circumnuclear Disk (CND) and other structures, using Herschel PACS and SPIRE photometric observations. These Herschel data are complemented by…

Astrophysics of Galaxies · Physics 2015-05-30 M. Etxaluze , H. A. Smith , V. Tolls , A. A. Stark , E. Gonzalez-Alfonso

An accurate estimate of the interstellar gas density distribution is crucial to understanding the interstellar medium (ISM) and Galactic cosmic rays (CRs). To comprehend the ISM and CRs in a local environment, a study of the diffuse…

High Energy Astrophysical Phenomena · Physics 2020-02-26 T. Mizuno , S. Abdollahi , Y. Fukui , K. Hayashi , T. Koyama , A. Okumura , H. Tajima , H. Yamamoto

The Warm Ionized Medium (WIM), also referred to as Diffuse Ionized Gas, contains most of the mass of interstellar medium in ionized form, contributing as much as 30% of the total atomic gas mass in the solar neighborhood. The advent of CCDs…

Astrophysics · Physics 2015-06-24 Rene A. M. Walterbos

We present CO observations of a large sample of ultraluminous IR galaxies out to z = 0.3. Most of the galaxies are interacting, but not completed mergers. All but one have high CO(1-0) luminosities, log(Lco [K-km/s-pc^2]) = 9.92 +/- 0.12.…

Astrophysics · Physics 2008-11-26 P. M. Solomon , D. Downes , S. J. E. Radford , J. W. Barrett

The most important cooling lines of the neutral interstellar medium (ISM) lie in the far-infrared (FIR). We present measurements by the Infrared Space Observatory Long Wavelength Spectrometer of seven lines from neutral and ionized ISM of…

We combine observations of spiral galaxies in the [CII] line at 158 micron, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main…

Astrophysics · Physics 2009-11-06 D. Pierini , J. Lequeux , A. Boselli , K. J. Leech , H. J. Voelk

We present mid-IR photometric properties for a sample of 28 early-type galaxies observed at 6.75, 9.63 and 15 um with the ISOCAM instrument on board the ISO satellite. We find total mid-IR luminosities in the range 3-48x10^8 L_sun. The…

Astrophysics · Physics 2009-11-07 F. Ferrari , M. G. Pastoriza , F. D. Macchetto , C. Bonatto , N. Panagia , W. B. Sparks , .

The Central Molecular Zone (CMZ), covering the inner ~1$^\circ$ of the Galactic plane has been mapped at 2 mm using the GISMO bolometric camera on the 30 m IRAM telescope. The $21''$ resolution maps show abundant emission from cold…

The origin of warm ions in the circum-galactic medium (CGM) surrounding massive galaxies remains a mystery. In this paper, we argue that a significant fraction of the observed warm-ion columns may arise in the intergalactic medium (IGM)…

Astrophysics of Galaxies · Physics 2025-07-08 Itai Bromberg , Kartick C. Sarkar , Orly Gnat , Yuval Brinboim

We present ISO observations of several H2 pure-rotational lines (from S(0) to S(5)) towards a sample of 16 molecular clouds distributed along the central ~ 500 pc of the Galaxy. We also present C18O and 13CO J=1->0 and J=2->1 observations…

The cooling transition temperature gas in the interstellar medium (ISM), traced by the high ions, Si IV, C IV, N V, and O VI, helps to constrain the flow of energy from the hot ISM with T >10^6 K to the warm ISM with T< 2x10^4 K. We…

Astrophysics of Galaxies · Physics 2015-05-20 N. Lehner , W. F. Zech , J. C. Howk , B. D. Savage

We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across 0.9 < z < 1.5 using 301 \lya absorption lines fitted from 12 HST STIS quasar spectra, with a total pathlength of \Delta z=2.1. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-06 Teng Hu , Vikram Khaire , Joseph F. Hennawi , Todd M. Tripp , Jose Oñorbe , Michael Walther , Zarija Lukic

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\Gamma_{\rm pe} = 1.2\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\cal…

Astrophysics · Physics 2008-11-03 Akio K. Inoue , Hideyuki Kamaya

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

High Energy Astrophysical Phenomena · Physics 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

A definite prediction from recent N-body/hydro simulations of the structure formation of the universe is the presence of a diffuse intergalactic medium (IGM) in a temperature range of 10^5 - 10^7 K. This hot phase of the IGM may account for…

Astrophysics · Physics 2007-05-23 Q. Daniel Wang

We use spectroscopic data from HST and FUSE to study the wide range of ionization states of the "highly ionized high-velocity clouds". Studied extensively in OVI absorption, these clouds are usually assumed to be infalling gas in the…

Astrophysics · Physics 2009-11-10 J. A. Collins , J. M. Shull , M. L. Giroux

We present model calculations of ionization fractions for elements in the warm (log T = 4), low-density photoionized interstellar medium (WIM) of the Milky Way. We model the WIM as a combination of overlapping low-excitation H II regions…

The Interstellar Medium (ISM) comprises gases at different temperatures and densities, including ionized, atomic, molecular species, and dust particles. The neutral ISM is dominated by neutral hydrogen and has ionization fractions up to 8%.…