R-C snubber for thyristor turn-off-a new approach

Popescu, Mihai Octavian; Nistor, D.; Popescu, Claudia Laurenta

doi:10.1109/isie.1996.548540

Cited by 10 publications

(12 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has also been found by several authors (Alton et al 1998b;Popescu & Tuffs 2002) that the bulk of the dust reveals itself when more sensitive dust indicators are used. Taken in this context, the SFM estimate (the thick line in Fig.…”

Section: Dust-to-hi Ratiomentioning

confidence: 66%

“…Spectral energy distribution modeling (SED) of edge-on galaxy disks (Popescu et al 2000;Misiriotis et al 2001;Popescu & Tuffs 2002) indicate that the dust's emission is powered by HII regions in the case of warm dust (λ < 100 µm) and diffuse stellar radiation in the case of cold dust (λ > 100 µm). The infrared flux is dominated by dust illuminated by nearby stars and an cold dust is only visible in the sub-mm part of the spectrum.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The opacity of spiral galaxy disks

Holwerda

Gonzalez

Allen³

et al. 2005

A&A

View full text Add to dashboard Cite

The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the "Synthetic Field Method" from González et al. (1998, ApJ, 506, 152), Holwerda et al. (2005a, AJ, 129, 1381. When compared for individual disks, the HI column density and dust opacity do not seem to be correlated as HI and opacity follow different radial profiles. To improve statistics, an average radial opacity profile is compared to an average HI profile. Compared to dust-to-HI estimates from the literature, more extinction is found in this profile. This difference may be accounted for by an underestimate of the dust in earlier measurements due to their dependence on dust temperature. Since the SFM is insensitive to the dust temperature, the ratio between the SFM opacity and HI could very well be indicative of the true ratio. Earlier claims for a radially extended cold dust disk were based on sub-mm observations. A comparison between sub-mm observations and counts of distant galaxies is therefore desirable. We present the best current example of such a comparison, M 51, for which the measurements seem to agree. However, this remains an area where improved counts of distant galaxies, sub-mm observations and our understanding of dust emissivity are needed.

show abstract

Section: Dust-to-hi Ratiomentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

The opacity of spiral galaxy disks

Holwerda

Gonzalez

Allen³

et al. 2005

A&A

View full text Add to dashboard Cite

show abstract

“…This contamination is strongest in the 24 m maps, which contain an extended background component that is probably produced in large part by dust heated by older stars (e.g., Popescu & Tuffs 2002;Gordon et al 2004). This diffuse component contributes 15%Y34% of the total 24 m luminosity of M51, depending precisely on how the separation between point sources and diffuse background is made (Paper I; Dale et al 2007).…”

Section: Aperture Photometry and Local Flux Measurementsmentioning

confidence: 99%

Star Formation in NGC 5194 (M51a). II. The Spatially Resolved Star Formation Law

Kennicutt

Calzetti

Walter

et al. 2007

ApJ

504

646

View full text Add to dashboard Cite

We have studied the relationship between the star formation rate (SFR), surface density, and gas surface density in the spiral galaxy M51a ( NGC 5194), using multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey (SINGS ). We introduce a new SFR index based on a linear combination of H emission-line and 24 m continuum luminosities, which provides reliable extinction-corrected ionizing fluxes and SFR densities over a wide range of dust attenuations. The combination of these extinction-corrected SFR densities with aperture synthesis H i and CO maps has allowed us to probe the form of the spatially resolved star formation law on scales of 0.5Y2 kpc. We find that the resolved SFR versus gas surface density relation is well represented by a Schmidt power law, which is similar in form and dispersion to the disk-averaged Schmidt law. We observe a comparably strong correlation of the SFR surface density with the molecular gas surface density, but no significant correlation with the surface density of atomic gas. The best-fitting slope of the Schmidt law varies from N ¼ 1:37 to 1.56, with zero point and slope that change systematically with the spatial sampling scale. We tentatively attribute these variations to the effects of areal sampling and averaging of a nonlinear intrinsic star formation law. Our data can also be fitted by an alternative parameterization of the SFR surface density in terms of the ratio of gas surface density to local dynamical time, but with a considerable dispersion.

show abstract

“…The absorbed fraction of the UV/optical light (highly dependent on morphology but typically 30 per cent for local Universe disc galaxies) is re-radiated at far-infrared (IR) wavelengths (Popescu & Tuffs 2002;Tuffs et al 2004;Driver et al 2008). Throughout this process gas is being drawn into the galaxy from the intergalactic medium (IGM; Keres et al 2005), outflows driven by supernova expel material (Veilleux, Cecil & Bland-Hawthorn 2005), and tidal interactions with neighbouring dark matter haloes may lead to further mass-loss (Toomre & Toomre 1972), or mergers (Lacey & Cole 1993), as well as driving gas to the core leading to re-ignition of the central supermassive black hole .…”

Section: Introductionmentioning

confidence: 99%