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Related papers: A Study of ISM of Dwarf Galaxies Using HI Power Sp…

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We estimate the \HI intensity fluctuation power spectrum for a sample of 18 spiral galaxies chosen from THINGS. Our analysis spans a large range of length-scales from $\sim 300 {\rm pc}$ to $\sim 16 {\rm kpc}$ across the entire galaxy…

Astrophysics of Galaxies · Physics 2012-08-28 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur

The power spectrum of HI intensity fluctuation of the interstellar medium carries information of the turbulence dynamics therein. We present a method to estimate the power spectrum of HI intensity fluctuation using radio interferometric…

Astrophysics of Galaxies · Physics 2009-05-22 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur

We develop a visibility based power spectrum estimator to probe the power spectrum directly from the interferometric observations and also estimate the errors in it. A numerical simulation of synthetic observations is also performed to…

Astrophysics of Galaxies · Physics 2011-02-23 Prasun Dutta

We measure the power spectrum of HI intensity fluctuations in the extremely faint (M_B ~ -10.9) dwarf galaxy DDO 210 using a visibility based estimator that is well suited in very low signal to noise ratio regimes. DDO 210's HI power…

Astrophysics · Physics 2009-11-11 Ayesha Begum , Jayaram N. Chengalur , Somnath Bharadwaj

HI spatial power spectra (PS) were determined for a sample of 24 nearby dwarf irregular galaxies selected from the LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes - The HI Nearby Galaxy Survey) sample. The two-dimensional…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Hong-Xin Zhang , Deidre A. Hunter , Bruce G. Elmegreen

Fourier transform power spectra of major axis cuts in V and Halpha images were made for a sample of 9 irregular galaxies. These power spectra reveal structure over a wide range of scales. For 6 of the galaxies the power spectrum slopes at…

Astrophysics · Physics 2009-11-10 Kyle W. Willett , Bruce G. Elmegreen , Deidre A. Hunter

We have measured the HI power spectrum of the nearly face-on spiral galaxy NGC628 (M74) using a visibility based estimator. The power spectrum is well fitted by a power law $P(U)=AU^{\alpha}$, with $\alpha =- 1.6\pm0.2$ over the length…

Astrophysics · Physics 2009-11-13 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur

We propose a method to determine the power spectrum of \HI column density fluctuations using radio-interferometric observations of 21-cm emission from the ISM of galaxies. We have used this to estimate the power spectra of six nearly face…

Astrophysics of Galaxies · Physics 2015-06-16 Prasun Dutta , Somnath Bharadwaj

Small-scale fluctuations of different tracers of the interstellar the medium can be used to study the nature of turbulence in astrophysical scales. Of these, the `continuum' emission traces the fluctuations integrated along the line of…

Astrophysics of Galaxies · Physics 2019-01-30 Samir Choudhuri , Nirupam Roy

Turbulent dynamics generate random fluctuations in density and velocity in the Interstellar Medium (ISM) of spiral and dwarf galaxies. Observationally, H~{\sc i} 21-cm radiation provides a good probe of these stochastic processes and helps…

Astrophysics of Galaxies · Physics 2018-05-30 Meera Nandakumar

Galaxy harassment is an important mechanism for the morphological evolution of galaxies in clusters. The spiral galaxy NGC 4254 in the Virgo cluster is believed to be a harassed galaxy. We have analyzed the power spectrum of HI emission…

Astrophysics of Galaxies · Physics 2015-05-18 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur

The popular halo model predicts that the power spectrum of the galaxy fluctuations is simply the sum of the large scale linear halo-halo power spectrum and the weighted power spectrum of the halo profile. Previous studies have derived halo…

Astrophysics · Physics 2009-11-10 Adrian A. Collister , Ofer Lahav

Interstellar turbulence shapes the HI distribution in the Milky Way (MW). How this affects large-scale statistical properties of HI column density across the MW remains largely unconstrained. We use approx 13,000 square-degree GALFA-HI…

Astrophysics of Galaxies · Physics 2023-10-24 Amit K. Mittal , Brian L Babler , Snezana Stanimirovic , Nickolas Pingel

Context. Understanding the dwarf galaxy population in low density environments is crucial for testing the LCDM cosmological model. The increase in diversity towards low mass galaxies is seen as an increase in the scatter of scaling…

HI line widths are typically interpreted as a measure of ISM turbulence, which is potentially driven by star formation. In an effort to better understand the possible connections between line widths and star formation, we have characterized…

Astrophysics of Galaxies · Physics 2015-06-12 Adrienne M. Stilp , Julianne J. Dalcanton , Steven R. Warren , Evan Skillman , Juergen Ott , Baerbel Koribalski

We present new, high sensitivity VLA observations of HI in four dwarf galaxies (UGCA 292, GR8, DDO 210, and DDO 216) and we use these data to study interactions between star formation and the interstellar medium. HI velocity dispersions and…

Astrophysics · Physics 2016-08-30 L. M. Young , L. van Zee , K. Y. Lo , R. C. Dohm-Palmer , M. E. Beierle

Neutral hydrogen (HI) velocity dispersions are believed to be set by turbulence in the interstellar medium (ISM). Although turbulence is widely believed to be driven by star formation (SF), recent studies have shown that this driving…

The radial profiles of gas, stars, and far ultraviolet radiation in 20 dwarf Irregular galaxies are converted to stability parameters and scale heights for a test of the importance of two-dimensional (2D) instabilities in promoting star…

Astrophysics of Galaxies · Physics 2015-06-03 Bruce G. Elmegreen , Deidre A. Hunter

We compute the power spectrum of galaxy density fluctuations in a recently completed redshift survey of optically-selected galaxies in the southern hemisphere (SSRS2). The amplitude and shape of the SSRS2 power spectrum are consistent with…

Astrophysics · Physics 2009-10-22 L. N. da Costa , M. S. Vogeley , M. J. Geller , J. P. Huchra , C. Park

We have measured the HI power spectrum of the nearly face-on spiral galaxy NGC 1058 from radio-interferometric observations using a visibility based estimator. The power spectrum is well fitted by two different power laws…

Astrophysics of Galaxies · Physics 2015-05-13 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur
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