Determining the Physical Properties of the B Stars. I. Methodology and First Results

Fitzpatrick, E. L.; Massa, Derck

doi:10.1086/307944

Cited by 69 publications

(85 citation statements)

References 37 publications

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“…For each star, the T eff and log(g) adopted by W&H were used, and each model photosphere was represented by an Kurucz LTE model atmosphere. Direct comparison to non-LTE model atmospheres (Grigsby 1991;Grigsby et al 1992) and to observed UV-to-optical spectral energy distributions (Fitzpatrick & Massa 1999) demonstrates that the approximation of LTE model atmospheres is a reasonable one for this range of stellar parameters.…”

Section: Calculationsmentioning

confidence: 94%

The interpretation of Mn II emission from late-type B stars

Sigut

2001

A&A

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Abstract. The photospheric Mn ii emission lines Wahlgren & Hubrig (2000) detect in the spectra of several late-type B and HgMn stars and attribute to fluorescent excitation are more naturally explained by interlocked non-LTE effects acting in a photosphere in which the manganese abundance is stratified with depth. The case is particularly strong for HD 186122 (46 Aql) and HD 179761 both of which require the manganese overabundance to be concentrated to column masses of log(m) < ≈ −1.5.

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Section: Calculationsmentioning

confidence: 94%

The interpretation of Mn II emission from late-type B stars

Sigut

2001

A&A

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“…After applying these criteria, we are left with a catalog of 332,037 sources consisting of 123,567 stars (37%) and 208,470 galaxies (63%), 195,426 (59%) of which satisfy Equation (18). We then correct for Galactic dust extinction using the Schlegel et al (1998) dust map and the extinction curve of Fitzpatrick & Massa (1999). Source-count histograms of the K s magnitudes for stars and the corrected K s magnitudes for galaxies are shown by the solid black and dashed blue lines, respectively, in Figure 6.…”

Section: Photometric Fittingmentioning

confidence: 99%

Constraining Agn Feedback in Massive Ellipticals With South Pole Telescope Measurements of the Thermal Sunyaev–zel’dovich Effect

Spacek

Scannapieco

Cohen

et al. 2016

ApJ

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Energetic feedback due to active galactic nuclei (AGNs) is likely to play an important role in the observed antihierarchical trend in the evolution of galaxies, and yet the energy injected into the circumgalactic medium by this process is largely unknown. One promising approach to constrain this feedback is through measurements of spectral distortions in the cosmic microwave background due to the thermal Sunyaev-Zeldovich (tSZ) effect, whose magnitude is directly proportional to the energy input by AGNs. With current instruments, making such measurements requires stacking large numbers of objects to increase signal-to-noise. While one possible target for such stacks is AGNs themselves, these are relatively scarce sources that contain contaminating emission that complicates tSZ measurements. Here we adopt an alternative approach and co-add South Pole Telescope SZ (SPT-SZ) survey data around a large set of massive quiescent elliptical galaxies at  z 0.5, which are much more numerous and less contaminated than active AGNs, yet are subject to the same feedback processes from the AGNs they hosted in the past. We use data from the Blanco Cosmology Survey and VISTA Hemisphere Survey to create a large catalog of galaxies split up into two redshift bins: one with 3394 galaxies at   z 0.5 1.0 and one with 924 galaxies at   z 1.0 1.5, with typical stellar masses of´ M 1.5 10 . 11We then co-add the emission around these galaxies, resulting in a measured tSZ signal at s 2.2 significance for the lower redshift bin and a contaminating signal at s 1.1 for the higher redshift bin. To remove contamination due to dust emission, we use SPT-SZ source counts to model a contaminant source population in both the SPT-SZ bands and Planck highfrequency bands for a subset of 937 galaxies in the low-redshift bin and 240 galaxies in the high-redshift bin. This increases our detection to s 3.6 for low redshifts and s 0.9 for high redshifts. We find the mean angularly integrated Compton-y values to be- 60 erg, respectively. These numbers are higher than expected from simple theoretical models that do not include AGN feedback, and serve as constraints that can be applied to current simulations of massive galaxy formation.

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“…10 For the optical and NIR filters we used the extinction coefficients from De . For the F275W and F336W filters we followed the prescription of De , adding 1.5 to the Fitzpatrick & Massa (1999) massive stars has always been hampered by their rarity, due to the short timescales involved in their evolution and the steepness of the IMF. On the theoretical side, models of massive stars are still affected by major uncertainties.…”

Section: Stellar Clocks: Ms Turn-off and Pms Turn-onmentioning

confidence: 99%

Hubble Tarantula Treasury Project. Ii. The Star-Formation History of the Starburst Region NGC 2070 in 30 Doradus

Cignoni

Sabbi

Marel

et al. 2015

ApJ

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We present a study of the recent star formation (SF) of 30 Doradus in the Large Magellanic Cloud (LMC) using the panchromatic imaging survey Hubble Tarantula Treasury Project. In this paper we focus on the stars within 20 pc of the center of 30 Doradus, the starburst region NGC 2070. We recovered the SF history by comparing deep optical and near-infrared color-magnitude diagrams (CMDs) with state-of-the-art synthetic CMDs generated with the latest PAdova and TRieste Stellar Evolution Code (PARSEC) models, which include all stellar phases from pre-main-sequence to post-main-sequence. For the first time in this region we are able to measure the SF using intermediate-and low-mass stars simultaneously. Our results suggest that NGC 2070 experienced prolonged activity. In particular, we find that the SF in the region (1) exceeded the average LMC rate ≈ 20 Myr ago, (2) accelerated dramatically ≈ 7 Myr ago, and (3) reached a peak value 1-3 Myr ago. We did not find significant deviations from a Kroupa initial mass function down to M 0.5  . The average internal reddening E B V ( ) -is found to be between 0.3 and 0.4 mag.

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Determining the Physical Properties of the B Stars. I. Methodology and First Results

Cited by 69 publications

References 37 publications

The interpretation of Mn II emission from late-type B stars

The interpretation of Mn II emission from late-type B stars

Constraining Agn Feedback in Massive Ellipticals With South Pole Telescope Measurements of the Thermal Sunyaev–zel’dovich Effect

Hubble Tarantula Treasury Project. Ii. The Star-Formation History of the Starburst Region NGC 2070 in 30 Doradus

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