Abstract The Star Formation History of Low Surface Brightness Galaxies
... The star formation histories of low surface brightness galaxies are interesting but poorly constrained. These objects tend to be rather blue, contradicting the initial impression that they may simply be faded remnants of higher surface brightness galaxies whose star formation has finished. Other sce ...
... The star formation histories of low surface brightness galaxies are interesting but poorly constrained. These objects tend to be rather blue, contradicting the initial impression that they may simply be faded remnants of higher surface brightness galaxies whose star formation has finished. Other sce ...
Super-Eddington outburst in a binary system: V4641 Sgr Mikhail Revnivtsev, Marat Gilfanov
... super-Eddington accretion • During this episode a powerful expended evelope was formed • When the accretion rate decreased the envelope vanished • X-ray observations support this picture: we have detected the change in the X-ray absorption column, smeared and probably delayed variability of ...
... super-Eddington accretion • During this episode a powerful expended evelope was formed • When the accretion rate decreased the envelope vanished • X-ray observations support this picture: we have detected the change in the X-ray absorption column, smeared and probably delayed variability of ...
Spot sizes on Sun-like stars
... 6 in Table 2) are taken from Henry et al. (1995), Rodonò et al. (2000) and Padmakar & Pandey (1999) and are labelled H+, R+ and PP, respectively, in column 7. The covering fractions derived from photometry by Henry et al. (1995) are lower limits as they have used the maximum light level during each ...
... 6 in Table 2) are taken from Henry et al. (1995), Rodonò et al. (2000) and Padmakar & Pandey (1999) and are labelled H+, R+ and PP, respectively, in column 7. The covering fractions derived from photometry by Henry et al. (1995) are lower limits as they have used the maximum light level during each ...
Read Claudia`s PhD thesis
... of GCs and dwarf spheroidals. They also appear less regular in shape as if they were in the process of being disrupted by tidal interactions. All these systems appear to be rather metal poor and show the presence of an ancient stellar component. We have ...
... of GCs and dwarf spheroidals. They also appear less regular in shape as if they were in the process of being disrupted by tidal interactions. All these systems appear to be rather metal poor and show the presence of an ancient stellar component. We have ...
Tuomas Kangas
... Different ways to gain information on the progenitor stars of core-collapse supernovae are explored, with an emphasis on using the environments of supernovae. In the articles included in the thesis, various such methods are demonstrated and utilized to constrain the progenitor stars of different typ ...
... Different ways to gain information on the progenitor stars of core-collapse supernovae are explored, with an emphasis on using the environments of supernovae. In the articles included in the thesis, various such methods are demonstrated and utilized to constrain the progenitor stars of different typ ...
THE PROMINENT DUST EMISSION FEATURE NEAR 8.9 m IN
... 8.6 m PAH emission feature. Similarly, Cesarsky et al. (1996) and Verstraete et al. (1996) found a broad, intense emission band at 8.7 m in the H ii region of M17, also clearly distinct from the 8.6 m PAH band found in the PDR and molecular cloud of M17. Therefore, this emission band is a new and ...
... 8.6 m PAH emission feature. Similarly, Cesarsky et al. (1996) and Verstraete et al. (1996) found a broad, intense emission band at 8.7 m in the H ii region of M17, also clearly distinct from the 8.6 m PAH band found in the PDR and molecular cloud of M17. Therefore, this emission band is a new and ...
A catalogue of the Chandra Deep Field South with multi
... MIDAS package. A WFI image processing pipeline was developed by Wolf et al. (2001) and makes intensive use of programmes developed by K. Meisenheimer, H.-J. Röser and H. Hippelein for the Calar Alto Deep Imaging Survey (CADIS). The pipeline performes basic image reduction and standard operations of ...
... MIDAS package. A WFI image processing pipeline was developed by Wolf et al. (2001) and makes intensive use of programmes developed by K. Meisenheimer, H.-J. Röser and H. Hippelein for the Calar Alto Deep Imaging Survey (CADIS). The pipeline performes basic image reduction and standard operations of ...
PDF - STRW Local - Universiteit Leiden
... While the haloes of dark matter that are thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, b ...
... While the haloes of dark matter that are thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, b ...
THE MORPHOLOGICAL DEMOGRAPHICS OF GALAXIES IN THE
... were f (R) = 2π 0R I(r)dr is the integrated flux within the radius R. The determination of the radius R up to where to integrate the light is of importance particularly for the asymmetry values. As we sample galaxies over ever larger cosmic ages, the surface brightness of galaxies at higher redshift ...
... were f (R) = 2π 0R I(r)dr is the integrated flux within the radius R. The determination of the radius R up to where to integrate the light is of importance particularly for the asymmetry values. As we sample galaxies over ever larger cosmic ages, the surface brightness of galaxies at higher redshift ...
The old Nuclear Star Cluster in the Milky Way
... statistical analysis with the results of Gillessen et al. (2009) based on orbits around Sgr A* gives M• = (4.23 ± 0.14) × 106 M and R0 = 8.33 ± 0.11 kpc. The constraint of the distance is particularly important since R0 acts as a scale factor for the Galactic structure and impacts mass estimations ...
... statistical analysis with the results of Gillessen et al. (2009) based on orbits around Sgr A* gives M• = (4.23 ± 0.14) × 106 M and R0 = 8.33 ± 0.11 kpc. The constraint of the distance is particularly important since R0 acts as a scale factor for the Galactic structure and impacts mass estimations ...
Extragalactic Astronomical Masers I
... Maser (Microwave Amplification by Stimulated Emission of Radiation) is a radio wave equivalent of laser at optical wavelength. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser is an artificial light and it is very different from other lights in that a laser ligh ...
... Maser (Microwave Amplification by Stimulated Emission of Radiation) is a radio wave equivalent of laser at optical wavelength. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser is an artificial light and it is very different from other lights in that a laser ligh ...
Uncovering the nucleus candidate for NGC 253
... Davies et al. 2014). Theses speculations are due mostly to the fact that an increasing number of the neighboring galaxies, as revealed by new observations, contain starbursts and active galactic nuclei (AGNs) in close proximity (see Levenson et al. 2001 and references therein). It remains unclear wh ...
... Davies et al. 2014). Theses speculations are due mostly to the fact that an increasing number of the neighboring galaxies, as revealed by new observations, contain starbursts and active galactic nuclei (AGNs) in close proximity (see Levenson et al. 2001 and references therein). It remains unclear wh ...
determination of the distance to the galactic centre nigel clayton
... Abstract: This paper summarises an investigation into the wide ranging methods employed to determine the distance to the Galactic centre, Ro. Remote methods commonly use luminosity reference objects such as RR Lyraes and red clump stars. Ruler methods involve annual parallax or line-of-sight velocit ...
... Abstract: This paper summarises an investigation into the wide ranging methods employed to determine the distance to the Galactic centre, Ro. Remote methods commonly use luminosity reference objects such as RR Lyraes and red clump stars. Ruler methods involve annual parallax or line-of-sight velocit ...
A Revised DDO Abundance Calibration for Population I Red Giants
... In consequence, the deviation in the position of a star from the standard sequence line in the (R-I) vs C(45–48) diagram, is an indicator of the amount of blanketing in the C (4548) index, and the same can be said for C(42–45). In order to determine the blanketing coefficients we proceeded as follow ...
... In consequence, the deviation in the position of a star from the standard sequence line in the (R-I) vs C(45–48) diagram, is an indicator of the amount of blanketing in the C (4548) index, and the same can be said for C(42–45). In order to determine the blanketing coefficients we proceeded as follow ...
Environmental dependence of bulge
... tail, where it curves upwards towards larger sizes. Compared to lower mass galaxies and previous work in the local Universe, the slope is in fact β ∼ 0.85 instead of the commonly reported slope of β ∼ 0.5–0.6 (e.g. Shen et al. 2003; Cimatti, Nipoti & Cassata 2012). This difference is mainly due to t ...
... tail, where it curves upwards towards larger sizes. Compared to lower mass galaxies and previous work in the local Universe, the slope is in fact β ∼ 0.85 instead of the commonly reported slope of β ∼ 0.5–0.6 (e.g. Shen et al. 2003; Cimatti, Nipoti & Cassata 2012). This difference is mainly due to t ...
Planet formation and migration
... in 1995 by Mayor & Queloz. It was detected from Haute–Provence Observatory, and immediately confirmed by Marcy & Butler (1995), who observed it from Lick Observatory (see the review by Marcy & Butler 1998 for more details about the detection of the first eight extrasolar planets) . Since then, there ...
... in 1995 by Mayor & Queloz. It was detected from Haute–Provence Observatory, and immediately confirmed by Marcy & Butler (1995), who observed it from Lick Observatory (see the review by Marcy & Butler 1998 for more details about the detection of the first eight extrasolar planets) . Since then, there ...
Finding Dark Matter
... • Light from a star or galaxy is bent by a massive object between it and the ...
... • Light from a star or galaxy is bent by a massive object between it and the ...
The binary fractions in the massive young Large Magellanic Cloud
... yield high detection efficiency, since it only depends on a single set of observations. In principle, one does not need to adopt many physical assumptions either; the approach is only based on our understanding of stellar evolution. This also allows us to simulate artificial observations for compari ...
... yield high detection efficiency, since it only depends on a single set of observations. In principle, one does not need to adopt many physical assumptions either; the approach is only based on our understanding of stellar evolution. This also allows us to simulate artificial observations for compari ...
Gamma Ray Bursts
... Diversity of pulse shapes well explained by diversity of shapes and sizes of comets. Neutron stars are inside galactic disk. How to get isotropic distribution? Possible, if we see only nearby neutron stars. Having the number of neutron stars (from pulsar observations and supernovae) and the numer of ...
... Diversity of pulse shapes well explained by diversity of shapes and sizes of comets. Neutron stars are inside galactic disk. How to get isotropic distribution? Possible, if we see only nearby neutron stars. Having the number of neutron stars (from pulsar observations and supernovae) and the numer of ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.