ABSTRACT We investigate the correlations between the black hole (BH) mass MBH, the velocity dispersion , the bulge mass MBu, the bulge average spherical density , and its spherical half-mass radius ...rh, constructing a database of 97 galaxies (31 core ellipticals, 17 power-law ellipticals, 30 classical bulges, and 19 pseudobulges) by joining 72 galaxies from the literature to 25 galaxies observed during our recent SINFONI BH survey. For the first time we discuss the full error covariance matrix. We analyze the well-known MBH- and MBH-MBu relations and establish the existence of statistically significant correlations between MBu and rh and anticorrelations between MBu and . We establish five significant bivariate correlations (MBH- - h, MBH- -rh, MBH-MBu- , MBH-MBu- h, MBH-MBu-rh) that predict MBH of 77 core and power-law ellipticals and classical bulges with measured and intrinsic scatter as small as dex and dex, respectively, or 0.26 dex when the subsample of 45 galaxies defined by Kormendy & Ho is considered. In contrast, pseudobulges have systematically lower MBH but approach the predictions of all of the above relations at spherical densities or scale lengths . These findings fit in a scenario of coevolution of BH and classical-bulge masses, where core ellipticals are the product of dry mergers of power-law bulges and power-law ellipticals and bulges the result of (early) gas-rich mergers and of disk galaxies. In contrast, the (secular) growth of BHs is decoupled from the growth of their pseudobulge hosts, except when (gas) densities are high enough to trigger the feedback mechanism responsible for the existence of the correlations between MBH and galaxy structural parameters.
New methods often spread by means of passionate individuals who see the greater perspective and purpose of the technique. The great challenge then, is to inspire local colleagues, superiors, ...administrators and technical staff. Accordingly, methods should provide a major advantage to previous methods or fill in a hitherto weak spot in the diagnostic armamentarium. A conservative attitude/skepticism over new methods can be due to: lack of first line evidence evidence exists, but implementation requires a major paradigm shift inertia and lack of resources in the system new methods require time and brains for implementation, some basic concepts may be hard to follow clinical interpretation may be difficult, it may pertain very few patients, and make it difficult to get experience methods may be extremely expensive and time consuming, limiting implementation to resourceful sites. The implementation process must be performed in an appreciative atmosphere, to motivate all parts. Often it is advisable to start with small scale implementation, then gradually including more of the staff. A do-plan-study-act approach is advised to optimize the method before large scale implementation.
We make publicly available a catalog of calibrated environmental measures for galaxies in the five 3D-Hubble Space Telescope (HST)/CANDELS deep fields. Leveraging the spectroscopic and grism ...redshifts from the 3D-HST survey, multiwavelength photometry from CANDELS, and wider field public data for edge corrections, we derive densities in fixed apertures to characterize the environment of galaxies brighter than mag in the redshift range . By linking observed galaxies to a mock sample, selected to reproduce the 3D-HST sample selection and redshift accuracy, each 3D-HST galaxy is assigned a probability density function of the host halo mass, and a probability that it is a central or a satellite galaxy. The same procedure is applied to a z = 0 sample selected from Sloan Digital Sky Survey. We compute the fraction of passive central and satellite galaxies as a function of stellar and halo mass, and redshift, and then derive the fraction of galaxies that were quenched by environment specific processes. Using the mock sample, we estimate that the timescale for satellite quenching is it is longer at lower stellar mass or lower redshift, but remarkably independent of halo mass. This indicates that, in the range of environments commonly found within the 3D-HST sample ( ), satellites are quenched by exhaustion of their gas reservoir in the absence of cosmological accretion. We find that the quenching times can be separated into a delay phase, during which satellite galaxies behave similarly to centrals at fixed stellar mass, and a phase where the star formation rate drops rapidly ( Gyr), as shown previously at z = 0. We conclude that this scenario requires satellite galaxies to retain a large reservoir of multi-phase gas upon accretion, even at high redshift, and that this gas sustains star formation for the long quenching times observed.
We present a census of ionized gas outflows in 599 normal galaxies at redshift 0.6 < z < 2.7, mostly based on integral field spectroscopy of Hα, N ii, and S ii line emission. The sample fairly ...homogeneously covers the main sequence of star-forming galaxies with masses 9.0 < log(M */M ⊙) < 11.7, and probes into the regimes of quiescent galaxies and starburst outliers. About one-third exhibits the high-velocity component indicative of outflows, roughly equally split into winds driven by star formation (SF) and active galactic nuclei (AGNs). The incidence of SF-driven winds correlates mainly with SF properties. These outflows have typical velocities of ∼450 km s−1, local electron densities of n e ∼ 380 cm−3, modest mass loading factors of ∼0.1–0.2 at all galaxy masses, and energetics compatible with momentum driving by young stellar populations. The SF-driven winds may escape from log(M */M ⊙) ≲ 10.3 galaxies, but substantial mass, momentum, and energy in hotter and colder outflow phases seem required to account for low galaxy formation efficiencies in the low-mass regime. Faster AGN-driven outflows (∼1000–2000 km s−1) are commonly detected above log(M */M ⊙) ∼ 10.7, in up to ∼75% of log(M */M ⊙) ≳ 11.2 galaxies. The incidence, strength, and velocity of AGN-driven winds strongly correlates with stellar mass and central concentration. Their outflowing ionized gas appears denser (n e ∼ 1000 cm−3), and possibly compressed and shock-excited. These winds have comparable mass loading factors as the SF-driven winds but carry ∼10 (∼50) times more momentum (energy). The results confirm our previous findings of high-duty-cycle, energy-driven outflows powered by AGN above the Schechter mass, which may contribute to SF quenching.
We present the completed KMOS3D survey, an integral field spectroscopic survey of 739 \(\mathrm{log}({M}_{\star }/{M}_{\odot })\gt 9\) galaxies at 0.6 < z < 2.7 using the K-band Multi Object ...Spectrograph (KMOS) at the Very Large Telescope. The KMOS3D survey provides a population-wide census of kinematics, star formation, outflows, and nebular gas conditions both on and off the star-forming galaxy main sequence through the spatially resolved and integrated properties of Hα, N ii, and S ii emission lines. We detect Hα emission for 91% of galaxies on the main sequence of star formation and 79% overall. The depth of the survey has allowed us to detect galaxies with star formation rates below 1 M ⊙ yr−1, as well as to resolve 81% of detected galaxies with ≥3 resolution elements along the kinematic major axis. The detection fraction of Hα is a strong function of both color and offset from the main sequence, with the detected and nondetected samples exhibiting different spectral energy distribution shapes. Comparison of Hα and UV+IR star formation rates reveal that dust attenuation corrections may be underestimated by 0.5 dex at the highest masses (\(\mathrm{log}({M}_{\star }/{M}_{\odot })\gt 10.5\)). We confirm our first year results of a high rotation-dominated fraction (monotonic velocity gradient and v rot/\({\sigma }_{0}\gt \sqrt{3.36}\)) of 77% for the full KMOS3D sample. The rotation-dominated fraction is a function of both stellar mass and redshift, with the strongest evolution measured over the redshift range of the survey for galaxies with \(\mathrm{log}({M}_{\star }/{M}_{\odot })\lt 10.5\). With this paper, we include a final data release of all 739 observed objects (http://www.mpe.mpg.de/ir/KMOS3D).
Digest Fenker, Jessica; McCulloch, Graham A.; Vasconcellos, Mariana Mira ...
Evolution,
08/2021, Letnik:
75, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Dispersal-associated traits —such as flight ability— influence how species move across the landscape, and can dramatically impact their distributions and patterns of genetic structure. Ortego et al. ...examine genomic data from two recently diverged alpine grasshopper lineages with distinct wing sizes to assess the demographic impacts of flight loss. The authors showed that flight loss may lead to asymmetric introgression during speciation, and can significantly increase rates of intraspecific diversification.
Traditionally focused on Amazonian and Atlantic rainforests, studies on the origins of high Neotropical biodiversity have recently shifted to also investigate biodiversity processes in the South ...American dry diagonal, encompassing Chaco, Cerrado savannas, and Caatinga seasonally dry tropical forests. The plateau/depression hypothesis states that riparian forests in the Brazilian Shield in central Brazil are inhabited by Pleistocene lineages, with shallow divergences and signatures of population expansion. Moreover, riparian forests may have acted as a vegetation network in the Pleistocene, allowing gene/species flow across the South American dry diagonal. We tested these hypotheses using Colobosaura modesta, a small gymnophthalmid lizard from forested habitats in the Cerrado savannas and montane/submontane forests in the Caatinga. We conducted phylogeographic analyses using a multi-locus dataset, tested alternative demographic scenarios with Approximate Bayesian Computation, and also employed species delimitation tests. We recovered a history of recent colonization and expansion along riparian forests, associated with Pleistocene climate shifts, and the existence of a new species of Colobosaura restricted to the Serra do Cachimbo region. We also present evidence that riparian forests have provided an interconnected network for forest organisms within the South American dry diagonal and that Pleistocene events played an important role in their evolutionary history.
Aim for heterogeneous biodiversity restoration Toma, Tiago S P; Oliveira, Hernani F M; Overbeck, Gerhard E ...
Science (American Association for the Advancement of Science),
01/2024, Letnik:
383, Številka:
6681
Journal Article
The most massive elliptical galaxies have low-density centers or cores that differ dramatically from the high-density centers of less massive ellipticals and bulges of disk galaxies. These cores have ...been interpreted as the result of mergers of supermassive black hole binaries, which depopulate galaxy centers by gravitationally slingshotting central stars toward large radii. Such binaries naturally form in mergers of luminous galaxies. Here, we analyze the population of central stellar orbits in 11 massive elliptical galaxies that we observed with the integral field spectrograph SINFONI at the European Southern Observatory Very Large Telescope. Our dynamical analysis is orbit-based and includes the effects of a central black hole, the mass distribution of the stars, and a dark matter halo. We show that the use of integral field kinematics and the inclusion of dark matter is important to conclude on the distribution of stellar orbits in galaxy centers. Six of our galaxies are core galaxies. In these six galaxies, but not in the galaxies without cores, we detect a coherent lack of stars on radial orbits in the core region and a uniform excess of radial orbits outside of it: when scaled by the core radius r sub(b), the radial profiles of the classical anisotropy parameter beta (r) are nearly identical in core galaxies. Moreover, they quantitatively match the predictions of black hole binary simulations, providing the first convincing dynamical evidence for core scouring in the most massive elliptical galaxies.
We present the first results of an analysis of the properties of the molecular gas in the nuclear regions (r 300 pc) of a sample of six nearby galaxies, based on new high-spatial-resolution ...observations obtained in the K-band with the near-infrared integral field spectrograph SINFONI at the Very Large Telescope. We derive 2D distributions of the warm molecular and ionized gas from the H2, Brγ and He i emission lines present in the spectra of the galaxies. We find a range of morphologies, including bar- and ring-like distributions and either centrally peaked or off-centre emission. The morphologies of the molecular and the ionized gas are not necessarily coincident. The observed emission-line ratios point towards thermal processes as the principal mechanism responsible for the H2 excitation in the nuclear and circumnuclear regions of the galaxies, independently of the presence of an active nucleus. We find that a rescaling of the H2 2.12 μm emission-line luminosity by a factor β 1200 gives a good estimate (within a factor of 2) of the total (cold) molecular gas mass. The galaxies of the sample contain large quantities of molecular gas in their centres, with total masses in the ∼105-108 M range. Nevertheless, these masses correspond to less than 3 per cent of the stellar masses derived for the galaxies in these regions, indicating that the presence of gas should not affect black hole mass estimates based on the dynamical modelling of the stars. The high spatial resolution provided by the SINFONI data allowed us to resolve a circumnuclear ring (with a radius of ∼270 pc) in the galaxy NGC 4536. The measured values of the Brγ equivalent width and the He i/Brγ emission-line ratio suggest that bursts of star formation occurred throughout this ring as recently as 6.5 Myr ago.
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