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相关论文: Implications for Galactic Electron Density Structu…

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We present here our shape analysis method for a sample of 76 Galactic HII regions from MAGPIS 1.4 GHz data. The main goal is to determine whether physical properties and initial conditions of massive star cluster formation is linked to the…

星系天体物理 · 物理学 2018-05-02 Justyn Campbell-White , Dirk Froebrich , Alfred Kume

We present here the results from an extensive scintillation study of twenty pulsars in the dispersion measure (DM) range 3 - 35 pc cm^-3 caried out using the Ooty Radio Telescope (ORT) at 327 MHz, to investigate the distribution of ionized…

天体物理学 · 物理学 2009-10-30 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

We report the discovery of two small intergalactic HII regions in the loose group of galaxies around the field elliptical NGC 1490. The HII regions are located at least 100 kpc from any optical galaxy but are associated with a number of…

天体物理学 · 物理学 2007-05-23 T. Oosterloo , R. Morganti , E. M. Sadler , A. Ferguson , J. M. van der Hulst , H. Jerjen

Mapping stars and gas in nearby galaxies is fundamental for understanding their growth and the impact of their environment. This issue is addressed by comparing the stellar "edges" of galaxies $D_{\rm stellar}$, defined as the outermost…

We present first deep VLT-spectra of a new class of compact extraplanar objects located in the disk-halo interface of the edge-on spiral galaxy NGC55. Their spectra reveal continuum emission from stars and show typical emission-lines as…

天体物理学 · 物理学 2009-11-10 R. Tuellmann , M. R. Rosa , T. Elwert , D. J. Bomans , A. M. N. Ferguson , R. -J. Dettmar

We constructed diagnostic diagrams using emission line ratios and equivalent widths observed in several samples of HII galaxies. The diagrams are compared to predictions from new photoionization models for evolving starbursts. We find that…

天体物理学 · 物理学 2009-11-06 Grazyna Stasinska , Daniel Schaerer , Claus Leitherer

We present a new catalogue of spectrophotometric distances and line-of-sight systemic velocities to 103 HII regions between 90$^{\circ}\leq \ell \leq~$195$^{\circ}$ (longitude quadrants II and part of III). Two new velocities for each…

星系天体物理 · 物理学 2015-10-21 Tyler J. Foster , Christopher M. Brunt

We present the [OIII]52{\mu}m map of the dwarf galaxy IC10, obtained with the Field-Imaging Far-Infrared Line Spectrometer (FIFI-LS) on board the Stratospheric Observatory for Infrared Astronomy (SOFIA). We combine the [OIII]52{\mu}m map…

We present high S/N measurements of the H I Ly alpha absorption line toward 16 Galactic targets which are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove…

星系天体物理 · 物理学 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

We present a pilot survey of 21 lines of sight towards UCHII regions in the H2CO 1-1 (6cm) and 2-2 (2cm) transitions, using the H2CO centimeter lines as a molecular gas densitometer. Using Arecibo and Green Bank beam-matched observations,…

星系天体物理 · 物理学 2011-07-27 Adam Ginsburg , Jeremy Darling , Cara Battersby , Ben Zeiger , John Bally

We determine the source of the diffuse [CII] emission by studying its spatial (radial and vertical) distributions. We used the HIFI [CII] Galactic survey (GOT C+), along with HI, 12CO, and 13CO data toward 354 lines of sight, and several…

星系天体物理 · 物理学 2014-12-03 T. Velusamy , W. D. Langer

Pulsed emission from almost one hundred millisecond pulsars (MSPs) has been detected in $\gamma$-rays by the Fermi Large-Area Telescope. The global properties of this population remain relatively unconstrained despite many attempts to model…

高能天体物理现象 · 物理学 2018-09-25 R. T. Bartels , T. D. P. Edwards , C. Weniger

We present the results of a study of young unresolved stellar groupings (clusters, OB associations, and their complexes) associated with HII regions, based on the coupling of spectroscopic, photometric and H{\alpha} spectrophotometric…

星系天体物理 · 物理学 2023-07-13 A. S. Gusev , F. Sakhibov , O. V. Egorov , V. S. Kostiuk , E. V. Shimanovskaya

Radio waves propagating from distant pulsars in the interstellar medium (ISM), are refracted by electron density inhomogeneities, so that the intensity of observed pulses fluctuates with time. The theory relating the observed pulse…

天体物理学 · 物理学 2009-11-10 Stanislav Boldyrev , Carl R. Gwinn

Stellar feedback is often cited as the biggest uncertainty in galaxy formation models today. This uncertainty stems from a dearth of observational constraints as well as the great dynamic range between the small scales (<1 pc) where the…

太阳与恒星天体物理 · 物理学 2015-06-17 Laura A. Lopez , Mark R. Krumholz , Alberto D. Bolatto , J. Xavier Prochaska , Enrico Ramirez-Ruiz , Daniel Castro

We study the structural evolution of turbulent molecular clouds under the influence of ionizing radiation emitted from a nearby massive star by performing a high resolution parameter study with the iVINE code. The temperature is taken to be…

太阳与恒星天体物理 · 物理学 2015-05-19 Matthias Gritschneder , Andreas Burkert , Thorsten Naab , Stefanie Walch

$\textit{Herschel}$ observations of far infrared N$^+$ emission lines have demonstrated that dense plasma, with $n_e\sim30\,{\rm cm^{-3}}$, is ubiquitous in the inner Galactic plane. By combining the information from $\textit{Herschel}$…

星系天体物理 · 物理学 2022-05-03 Marisa Geyer , Mark Walker

We analyze the distribution of the interstellar matter in the environs of the HII region Gum31, excited by the open cluster NGC3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the…

天体物理学 · 物理学 2009-11-13 C. Cappa , V. S. Niemela , R. Amorin , J. Vasquez

Pulsars are remarkable objects that emit across the entire electromagnetic spectrum, providing a powerful probe of the interstellar medium. In this study, we investigate the relation between dispersion measure (DM) and X-ray absorption…

高能天体物理现象 · 物理学 2015-06-15 C. He , C. -Y. Ng , V. M. Kaspi

Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on five-year time scales, far in excess of signals of…