The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

Niv Drory - One of the best experts on this subject based on the ideXlab platform.

  • sdss iv manga excavating the fossil record of stellar populations in Spiral Galaxies
    Monthly Notices of the Royal Astronomical Society, 2020
    Co-Authors: Thomas Peterken, M R Merrifield, Alfonso Aragonsalamanca, Amelia Frasermckelvie, V Avilareese, Rogerio Riffel, Johan H Knapen, Niv Drory
    Abstract:

    We perform a “fossil record” analysis for ≈800 low-redshift Spiral Galaxies, using STARLIGHT applied to integral field spectroscopic observations from the SDSS-IV MaNGA survey to obtain fully spatially-resolved high-resolution star formation histories (SFHs). From the SFHs, we are able to build maps indicating the present-day distribution of stellar populations of different ages in each galaxy. We find small negative mean age gradients in most Spiral Galaxies, especially at high stellar mass, which reflects the formation times of stellar populations at different galactocentric radii. We show that the youngest (109.5 years), again with a strong dependence on stellar mass. By interpreting the radial profiles of “time slices” as indicative of the size of the galaxy at the time those populations had formed, we are able to trace the simultaneous growth in mass and size of the Spiral Galaxies over the last 10 Gyr. Despite finding that the evolution of the measured light-weighted radius is consistent with inside-out growth in the majority of Spiral Galaxies, the evolution of an equivalent mass-weighted radius has changed little over the same time period. Since radial migration effects are likely to be small, we conclude that the growth of disks in Spiral Galaxies has occurred predominantly through an inside-out mode (with the effect greatest in high-mass Galaxies), but this has not had anywhere near as much impact on the distribution of mass within Spiral Galaxies.

Johan H Knapen - One of the best experts on this subject based on the ideXlab platform.

  • sdss iv manga excavating the fossil record of stellar populations in Spiral Galaxies
    Monthly Notices of the Royal Astronomical Society, 2020
    Co-Authors: Thomas Peterken, M R Merrifield, Alfonso Aragonsalamanca, Amelia Frasermckelvie, V Avilareese, Rogerio Riffel, Johan H Knapen, Niv Drory
    Abstract:

    We perform a “fossil record” analysis for ≈800 low-redshift Spiral Galaxies, using STARLIGHT applied to integral field spectroscopic observations from the SDSS-IV MaNGA survey to obtain fully spatially-resolved high-resolution star formation histories (SFHs). From the SFHs, we are able to build maps indicating the present-day distribution of stellar populations of different ages in each galaxy. We find small negative mean age gradients in most Spiral Galaxies, especially at high stellar mass, which reflects the formation times of stellar populations at different galactocentric radii. We show that the youngest (109.5 years), again with a strong dependence on stellar mass. By interpreting the radial profiles of “time slices” as indicative of the size of the galaxy at the time those populations had formed, we are able to trace the simultaneous growth in mass and size of the Spiral Galaxies over the last 10 Gyr. Despite finding that the evolution of the measured light-weighted radius is consistent with inside-out growth in the majority of Spiral Galaxies, the evolution of an equivalent mass-weighted radius has changed little over the same time period. Since radial migration effects are likely to be small, we conclude that the growth of disks in Spiral Galaxies has occurred predominantly through an inside-out mode (with the effect greatest in high-mass Galaxies), but this has not had anywhere near as much impact on the distribution of mass within Spiral Galaxies.

Yoshiaki Sofue - One of the best experts on this subject based on the ideXlab platform.

  • rotation and mass in the milky way and Spiral Galaxies
    Publications of the Astronomical Society of Japan, 2017
    Co-Authors: Yoshiaki Sofue
    Abstract:

    [PASJ Review Paper] Rotation curves are the basic tool for deriving the distribution of mass in Spiral Galaxies. In this review, we describe various methods to measure rotation curves in the Milky Way and Spiral Galaxies. We then describe two major methods to calculate the mass distribution using the rotation curve. By the direct method, the mass is calculated from rotation velocities without employing mass models. By the decomposition method, the rotation curve is deconvolved into multiple mass components by model fitting assuming a black hole, bulge, exponential disk and dark halo. The decomposition is useful for statistical correlation analyses among the dynamical parameters of the mass components. We also review recent observations and derived results. ( Full resolution copy is available at URL: this http URL )

  • rotation curves of Spiral Galaxies
    Annual Review of Astronomy and Astrophysics, 2001
    Co-Authors: Yoshiaki Sofue, Vera C Rubin
    Abstract:

    ▪ Abstract Rotation curves of Spiral Galaxies are the major tool for determining the distribution of mass in Spiral Galaxies. They provide fundamental information for understanding the dynamics, ev...

Thomas Peterken - One of the best experts on this subject based on the ideXlab platform.

  • sdss iv manga excavating the fossil record of stellar populations in Spiral Galaxies
    Monthly Notices of the Royal Astronomical Society, 2020
    Co-Authors: Thomas Peterken, M R Merrifield, Alfonso Aragonsalamanca, Amelia Frasermckelvie, V Avilareese, Rogerio Riffel, Johan H Knapen, Niv Drory
    Abstract:

    We perform a “fossil record” analysis for ≈800 low-redshift Spiral Galaxies, using STARLIGHT applied to integral field spectroscopic observations from the SDSS-IV MaNGA survey to obtain fully spatially-resolved high-resolution star formation histories (SFHs). From the SFHs, we are able to build maps indicating the present-day distribution of stellar populations of different ages in each galaxy. We find small negative mean age gradients in most Spiral Galaxies, especially at high stellar mass, which reflects the formation times of stellar populations at different galactocentric radii. We show that the youngest (109.5 years), again with a strong dependence on stellar mass. By interpreting the radial profiles of “time slices” as indicative of the size of the galaxy at the time those populations had formed, we are able to trace the simultaneous growth in mass and size of the Spiral Galaxies over the last 10 Gyr. Despite finding that the evolution of the measured light-weighted radius is consistent with inside-out growth in the majority of Spiral Galaxies, the evolution of an equivalent mass-weighted radius has changed little over the same time period. Since radial migration effects are likely to be small, we conclude that the growth of disks in Spiral Galaxies has occurred predominantly through an inside-out mode (with the effect greatest in high-mass Galaxies), but this has not had anywhere near as much impact on the distribution of mass within Spiral Galaxies.

  • sdss iv manga spatially resolved dust attenuation in Spiral Galaxies
    arXiv: Astrophysics of Galaxies, 2020
    Co-Authors: Michael J Greener, Thomas Peterken, M R Merrifield, Alfonso Aragonsalamanca, Amelia Frasermckelvie, Karen L Masters, Coleman M Krawczyk, Nicholas F Boardman, M Boquien, Brett H Andrews
    Abstract:

    Dust attenuation in star-forming Spiral Galaxies affects stars and gas in different ways due to local variations in dust geometry. We present spatially resolved measurements of dust attenuation for a sample of 232 such star-forming Spiral Galaxies, derived from spectra acquired by the SDSS-IV MaNGA survey. The dust attenuation affecting the stellar populations of these Galaxies (obtained using full spectrum stellar population fitting methods) is compared with the dust attenuation in the gas (derived from the Balmer decrement). Both of these attenuation measures increase for local regions of Galaxies with higher star formation rates; the dust attenuation affecting the stellar populations increases more so than the dust attenuation in the gas, causing the ratio of the dust attenuation affecting the stellar populations to the dust attenuation in the gas to decrease for local regions of Galaxies with higher star formation rate densities. No systematic difference is discernible in any of these dust attenuation quantities between the Spiral arm and inter-arm regions of the Galaxies. While both the dust attenuation in the gas and the dust attenuation affecting the stellar populations decrease with galactocentric radius, the ratio of the two quantities does not vary with radius. This ratio does, however, decrease systematically as the stellar mass of the galaxy increases. Analysis of the radial profiles of the two dust attenuation measures suggests that there is a disproportionately high concentration of birth clouds (incorporating gas, young stars and clumpy dust) nearer to the centres of star-forming Spiral Galaxies.

Paolo Salucci - One of the best experts on this subject based on the ideXlab platform.

  • The radial Tully–Fisher relation for Spiral Galaxies – I
    Monthly Notices of the Royal Astronomical Society, 2007
    Co-Authors: Irina A. Yegorova, Paolo Salucci
    Abstract:

    We find a new Tully-Fisher-like relation for Spiral Galaxies holding at different galactocentric radii. This Radial Tully-Fisher (RTF) relation allows us to investigate the distribution of matter in the optical regions of Spiral Galaxies. This relation, applied to three different samples of rotation curves of Spiral Galaxies, directly proves that: 1) the rotation velocity of Spirals is a good measure of their gravitational potential and both the RC’s amplitudes and profiles are well predicted by galaxy luminosity 2) the existence of a dark component, less concentrated than the luminous one, and 3) a scaling law, according to which, inside the disk optical size: Mdark/Mlum = 0.5(LB/10 11 LB⊙) −0.7 .

  • The Tully-Fisher relation of Spiral Galaxies
    Proceedings of the International Astronomical Union, 2005
    Co-Authors: Irina A. Yegorova, Paolo Salucci
    Abstract:

    salucci@sissa.it The Tully-Fisher (TF) relation is an empirically establish correlation between the luminosity of Spiral galaxy and its rotational velocity (Tully-Fisher, 1977). We used the Tully-Fisher relation in order to probe the dark matter (DM) distribution in the optical regions of Spiral Galaxies. We investigated a sample of rotation curves that includes 957 Galaxies. The new technique applied takes advantages on the full knowledge of the galaxy rotation curves.

  • The dark matter content of Spiral Galaxies
    The Astrophysical Journal, 1991
    Co-Authors: Paolo Salucci, Keith M. Ashman, Massimo Persic
    Abstract:

    We present a new technique for calculating the fraction of dark material within the optical radius of Spiral Galaxies. The method employs the well-established observational result that Spiral Galaxies have similar central surface brightnesses, as well as published stellar synthesis evolutionary models, color-magnitude relations and optical rotation curves. No assumptions about the dark matter distribution are necessary. We find that the ratio of disk-to-dynamical mass within the optical radius increases roughly as L B 0.4 . This is in good agreement with the results of Persic and Salucci which are derived from independent considerations

  • Dark matter in Spiral Galaxies
    The Astrophysical Journal, 1990
    Co-Authors: Massimo Persic, Paolo Salucci
    Abstract:

    The Tully-Fisher relation is used to probe dark matter (DM) in the optical regions of Spiral Galaxies. By establishing it at several different isophotal radii in an appropriate sample of 58 Galaxies with good B-band photometry and rotation curves, it is shown that some of its attributes (such as scatter, residuals, nonlinearity, and bias) dramatically decrease moving from the disk edge inward. This behavior challenges any mass model which assumes no DM or a luminosity-independent DM mass fraction interior to the optical radius of Spiral Galaxies. 58 refs.