2,022 research outputs found

    MUFASA: The strength and evolution of galaxy conformity in various tracers

    Get PDF
    We investigate galaxy conformity using the Mufasa cosmological hydrodynamical simulation. We show a bimodal distribution in galaxy colour with radius, albeit with too many low-mass quenched satellite galaxies compared to observations. Mufasa produces conformity in observed properties such as colour, sSFR, and Hi content; i.e neighbouring galaxies have similar properties. We see analogous trends in other properties such as in environment, stellar age, H2 content, and metallicity. We intro- duce quantifying conformity using S(R), measuring the relative difference in upper and lower quartile properties of the neighbours.We show that low-mass and non-quenched haloes have weak conformity (S(R) < 0.5) extending to large projected radii R in all properties, while high-mass and quenched haloes have strong conformity (S(R) ~ 1) that diminishes rapidly with R and disappears at R & 1 Mpc. S(R) is strongest for environment in low-mass haloes, and sSFR (or colour) in high-mass haloes, and is dominated by one-halo conformity with the exception of Hi in small haloes. Metal- licity shows a curious anti-conformity in massive haloes. Tracking the evolution of conformity for z = 0 galaxies back in time shows that conformity broadly emerges as a late-time (z < 1) phenomenon. However, for fixed halo mass bins, conformity is fairly constant with redshift out to z > 2. These trends are consistent with the idea that strong conformity only emerges once haloes grow above Mufasa’s quenching mass scale of ~ 1012M⊙. A quantitative measure of conformity in various properties, along with its evolution, thus represents a new and stringent test of the impact of quenching on environment within current galaxy formation models.ScopusIS

    Confirmation of the detection of B-modes in the Planck polarization maps

    Full text link
    One of the main problems for extracting the Cosmic Microwave Background (CMB) from submm/mm observations is to correct for the Galactic components, mainly synchrotron, free - free and thermal dust emission with the required accuracy. Through a series of papers, it has been demonstrated that this task can be fulfilled by means of simple neural networks with high confidence. The main purpose of this paper is to demonstrate that the CMB BB power spectrum detected in the Planck 2015 polarization maps is present in the improved Planck 2017 maps with higher signal-to-noise ratio. Two features have been detected in the EB power spectrum in the new data set, both with S/N \sim4 . The origin of these features is most likely leakage from E to B with a level of about 1 per cent. This leakage gives no significant contribution to the detected BB power spectrum. The TB power spectrum is consistent with a zero signal. Altogether, the BB power spectrum is not consistent with the 'canonical' tensor-to-scalar models combined with gravitational lensing spectra. These results will give additional strong arguments for support to the proposed polarization satellite projects to follow up on the Planck mission .Comment: accepted for puplication in Astronomical Note

    Hallazgo de un manuscrito sobre el "balsamo de Malats"

    Get PDF
    El autor halló en un libro de "Medicina y Cirugía Humana" de 1753, un manuscrito anónimo del famoso Bálsamo de Malats. Estimado en la primera mitad del 1800. Dos variantes. Se adjuntan las fotocopias, que ha traducido del catalán antiguo. Comparando la fórmula del Bálsamo con otras publicaciones de 1820

    A phase type survival tree model for clustering patients’ hospital length of stay

    Get PDF
    Clinical investigators, health professionals and managers are often interested in developing criteria for clustering patients into clinically meaningful groups according to their expected length of stay. In this paper, we propose phase-type survival trees which extend previous work on exponential survival trees. The trees are used to cluster the patients with respect to length of stay where partitioning is based on covariates such as gender, age at the time of admission and primary diagnosis code. Likelihood ratio tests are used to determine optimal partitions. The approach is illustrated using nationwide data available from the English Hospital Episode Statistics (HES) database on stroke-related patients, aged 65 years and over, who were discharged from English hospitals over a 1-year period.peer-reviewe

    An evolutionary missing link? A modest-mass early-type galaxy hosting an oversized nuclear black hole

    Get PDF
    SAGE1C J053634.78-722658.5 is a galaxy at redshift z = 0.14, discovered behind the Large Magellanic Cloud in the Spitzer Space Telescope`Surveying the Agents of Galaxy Evolution' Spectroscopy survey. It has very strong silicate emission at 10 μm but negligible far-IR and UV emission. This makes it a candidate for a bare active galactic nuclei (AGN) source in the IR, perhaps seen pole-on, without significant IR emission from the host galaxy. In this paper we present optical spectra taken with the Southern African Large Telescope to investigate the nature of the underlying host galaxy and its AGN. We find broad H α emission characteristic of an AGN, plus absorption lines associated with a mature stellar population (>9 Gyr), and refine its redshift determination to z = 0.1428 ± 0.0001. There is no evidence for any emission lines associated with star formation. This remarkable object exemplifies the need for separating the emission from any AGN from that of the host galaxy when employing IR diagnostic diagrams. We estimate the black hole mass, MBH = 3.5 ± 0.8 × 108 M⊙, host galaxy mass, M_stars=2.5^{2.5}_{1.2}× 10^{10} M⊙, and accretion luminosity, Lbol(AGN) = 5.3 ± 0.4 × 1045 erg s-1 (≈12 per cent of the Eddington luminosity), and find the AGN to be more prominent than expected for a host galaxy of this modest size. The old age is in tension with the downsizing paradigm in which this galaxy would recently have transformed from a star-forming disc galaxy into an early-type, passively evolving galaxy

    089 - Jucunda Semper

    Get PDF

    038 - Laetitiae Sanctae

    Get PDF

    Exponentially growing bubbles around early super massive black holes

    Get PDF
    We addressed the so far unexplored issue of outflows induced by exponentially growing power sources, focusing on early supermassive black holes (BHs). We assumed that these objects grow to 109  M10^9\;M_{\odot} by z=6 by Eddington-limited accretion and convert 5% of their bolometric output into a wind. We first considered the case of energy-driven and momentum-driven outflows expanding in a region where the gas and total mass densities are uniform and equal to the average values in the Universe at z>6z>6. We derived analytic solutions for the evolution of the outflow, finding that, for an exponentially growing power with e-folding time tSalt_{Sal}, the late time expansion of the outflow radius is also exponential, with e-folding time of 5tSal5t_{Sal} and 4tSal4t_{Sal} in the energy-driven and momentum-driven limit, respectively. We then considered energy-driven outflows produced by QSOs at the center of early dark matter halos of different masses and powered by BHs growing from different seeds. We followed the evolution of the source power and of the gas and dark matter density profiles in the halos from the beginning of the accretion until z=6z=6. The final bubble radius and velocity do not depend on the seed BH mass but are instead smaller for larger halo masses. At z=6, bubble radii in the range 50-180 kpc and velocities in the range 400-1000 km s1^{-1} are expected for QSOs hosted by halos in the mass range 3×10111013  M3\times10^{11}-10^{13}\;M_{\odot}. By the time the QSO is observed, we found that the total thermal energy injected within the bubble in the case of an energy-driven outflow is Eth5×1060E_{th}\sim5 \times 10^{60} erg. This is in excellent agreement with the value of Eth=(6.2±1.7)×1060E_{th}=(6.2\pm 1.7)\times 10^{60} erg measured through the detection of the thermal Sunyaev-Zeldovich effect around a large population of luminous QSOs at lower redshift. [abridged]Comment: 17 pages and 14 figures. Typos corrected. It matches the version published in A&
    corecore