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Сахибов, Ф. Х.; Смирнов, М. А.

doi:10.1023/a:1012706111868

Cited by 26 publications

(35 citation statements)

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“…The standard deviation in the measured distribution is 0.91, and the authors estimate the standard error of their method to be 0.51. Therefore the measured distribution of slopes is meaningful [34]. Because the total number of analysed star formation complexes is rather large, the formal probability of measuring such a large standard deviation is basically negligible (< 10 −10 ), if one assumes a universal IMF.…”

Section: Extragalactic Star Formation Complexesmentioning

confidence: 99%

“…A recent example for such a statistical approach is [34], who have included 105 extragalactic star formation complexes for which UBVR photometry, Lyman continuum flux, metallicity and extinction measurements were available. These properties trace essentially the high mass stellar content, and the results are restricted to the IMF for stars more massive than 10 M ⊙ .…”

Section: Extragalactic Star Formation Complexesmentioning

confidence: 99%

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Evidence in Favour of IMF Variations

Eisenhauer

2001

Starburst Galaxies: Near and Far

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Abstract. The stellar initial mass function (IMF) determines the relative number of stars born at a given mass. Despite the tremendous effort to establish a universal IMF, the astronomical literature offers a wealth of diverse evidence for IMF variations. This review was prepared for a controversial debate at the conference "Starbursts -Near and Far" at Ringberg Castle, 2000, and gives a one-sided portrayal in favour of IMF variations. I will summarise the empirical evidence that the IMF varies with time, with environment, and for all stellar masses. While I see no obvious systematic trend in most regions of our Galaxy, there is at least an indication that the IMF is biased towards more massive stars in the early universe and in starbursts.

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Section: Extragalactic Star Formation Complexesmentioning

confidence: 99%

Section: Extragalactic Star Formation Complexesmentioning

confidence: 99%

Evidence in Favour of IMF Variations

Eisenhauer

2001

Starburst Galaxies: Near and Far

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“…Figure 1 shows the H I map overlaid with the footprints of 29 Hubble Space Telescope (HST) fields. We also use the Hα (KPNO; Hoopes et al 2001) and 24 μm (Spitzer; Dale Rots (1975) 12 Roberts et al (1975) 11.5 Visser (1980) 13 Sakhibov & Smirnov (1987) >12.86 Elmegreen et al (1989) 9.84 Lowe et al (1994) 10.52 Westpfahl (1998) 9.8 Kendall et al (2008) 12.67 Tamburro et al (2008) 9. 23 Feng et al (2014) 9.5…”

Section: Datamentioning

confidence: 99%

Testing Density Wave Theory With Resolved Stellar Populations Around Spiral Arms in M81

Choi

Dalcanton

Williams

et al. 2015

ApJ

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Stationary density waves rotating at a constant pattern speed W P would produce age gradients across spiral arms. We test whether such age gradients are present in M81 by deriving the recent star formation histories (SFHs) of 20 regions around one of M81ʼs grand-design spiral arms. For each region, we use resolved stellar populations to determine the SFH by modeling the observed color-magnitude diagram constructed from archival Hubble Space Telescope F435W and F606W imaging. Although we should be able to detect systematic time delays in our spatially resolved SFHs, we find no evidence of star formation propagation across the spiral arm. Our data therefore provide no convincing evidence for a stationary density wave with a single pattern speed in M81, and instead favor the scenario of kinematic spiral patterns that are likely driven by tidal interactions with the companion galaxies M82 and NGC 3077.

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“…In turn, NGC 253 is a starburst galaxy with a rather high disk inclination, inappropriate for tracing spiral arms. However, later works by Sakhibov & Smirnov (1987, 1989, 1990 made it evident that the main problem of these early approaches is that independent determination of the rotation curve and of the residual velocities related to a density wave is not possible even for an "ideal" two-armed grand design galaxy. This conclusion was based on the analysis of the line-of-sight velocity fields of some galaxies by applying a Fourier-series expansion of velocity along the galactocentric azimuthal angle.…”

Section: Introductionmentioning

confidence: 99%

The orientation parameters and rotation curves of 15 spiral galaxies

Fridman

Afanasiev

Додонов

et al. 2005

A&A

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Abstract. We analyzed ionized gas motion and disk orientation parameters for 15 spiral galaxies. Their velocity fields were measured with the Hα emission line by using the Fabry-Perot interferometer at the 6 m telescope of SAO RAS. Special attention is paid to the problem of estimating the position angle of the major axis (PA 0 ) and the inclination (i) of a disk, which strongly affect the derived circular rotation velocity. We discuss and compare different methods of obtaining these parameters from kinematic and photometric observations, taking into account the presence of regular velocity (brightness) perturbations caused by spiral density waves. It is shown that the commonly used method of tilted rings may lead to systematic errors in the estimation of orientation parameters (and hence of circular velocity) being applied to galaxies with an ordered spiral structure. Instead we recommend using an assumption of constancy of i and PA 0 along a radius, to estimate these parameters. For each galaxy of our sample we present monochromatic Hα-and continuum maps, velocity fields of ionized gas, and the mean rotation curves in the frame of a model of pure circular gas motion. Significant deviations from circular motion with amplitudes of several tens of km s −1 (or higher) are found in almost all galaxies. The character and possible nature of the non-circular motion are briefly discussed.

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Cited by 26 publications

References 0 publications

Evidence in Favour of IMF Variations

Evidence in Favour of IMF Variations

Testing Density Wave Theory With Resolved Stellar Populations Around Spiral Arms in M81

The orientation parameters and rotation curves of 15 spiral galaxies

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