800 research outputs found
A critical period for robust curriculum-based deep reinforcement learning of sequential action in robot arm
Action Contro
Measuring supermassive black holes with gas kinematics - II. The LINERs IC 989, NGC 5077, and NGC 6500
We present results from a kinematical study of the gas in the nucleus of a
sample of three LINER galaxies, obtained from archival HST/STIS long-slit
spectra. We found that, while for the elliptical galaxy NGC 5077, the observed
velocity curves are consistent with gas in regular rotation around the galaxy's
center, this is not the case for the two remaining objects. By modeling the
surface brightness distribution and rotation curve from the emission lines in
NGC 5077, we found that the observed kinematics of the circumnuclear gas can be
accurately reproduced by adding to the stellar mass component a black hole mass
of M_bh = 6.8 (-2.8,+4.3) 10**8 M_sun (uncertainties at a 1 sigma level); the
radius of its sphere of influence (R_sph ~ 0".34) is well-resolved at the HST
resolution. The BH mass estimate in NGC 5077 is in fairly good agreement with
both the M_bh-M_bul (with an upward scatter of ~ 0.4 dex) and M_bh-sigma
correlations (with an upward scatter of 0.5 dex in the Tremaine et al. form and
essentially no scatter using the Ferrarese et al. form) and provides further
support for the presence of a connection between the ``residuals'' from the
M_bh-sigma correlation and the bulge effective radius. This indicates the
presence of a black hole's ``fundamental plane'' in the sense that a
combination of at least sigma and R_e drives the correlations between M_bh and
host bulge properties.Comment: Accepted for publication in A&
Resource constraints in successful climate policy : key constraints and bottlenecks, and some solutions
Industrial Ecolog
European principles of care for physiotherapy provision for persons with inherited bleeding disorders: Perspectives of physiotherapists and patients
Introduction: In their Chronic Care Model, the World Health Organisation states that people with chronic disorders and their families should be informed about the expected course, potential complications, and effective strategies to prevent complications and manage symptoms. Physiotherapists are a key professional group involved in the triage, assessment and management of musculoskeletal conditions of persons with a bleeding disorder (PWBD). Nevertheless, recent reports describe access to physiotherapy for those with these conditions is only sometimes available.
Aim: Access to high quality individualised physiotherapy should be ensured for all PWBD, including those with mild and moderate severities, male and female, people with von Willebrand Disease (vWD) and other rare bleeding disorders. Physiotherapy should be viewed as a basic requisite in their multidisciplinary care.
Methods/ results: Following a series of meetings with physiotherapists representing the European Association for Haemophilia and Allied Disorders (EAHAD) and PWBD representing the European Haemophilia Consortium (EHC) and a review of publications in the field, eight core principles of physiotherapy care for persons with a bleeding disorder have been co-produced by EAHAD and EHC.
Conclusion: These eight principles outline optimum standards of practice in order to advocate personalised patient-centred care for physical health in which both prevention and interventions include shared decision making, and supported self-management
The counterrotating core and the black hole mass of IC1459
The E3 giant elliptical galaxy IC1459 is the prototypical galaxy with a fast
counterrotating stellar core. We obtained one HST/STIS long-slit spectrum along
the major axis of this galaxy and CTIO spectra along five position angles. We
present self-consistent three-integral axisymmetric models of the stellar
kinematics, obtained with Schwarzschild's numerical orbit superposition method.
We study the dynamics of the kinematically decoupled core (KDC) in IC1459 and
we find it consists of stars that are well-separated from the rest of the
galaxy in phase space. The stars in the KDC counterrotate in a disk on orbits
that are close to circular. We estimate that the KDC mass is ~0.5% of the total
galaxy mass or ~3*10^9 Msun. We estimate the central black hole mass M_BH of
IC1459 independently from both its stellar and its gaseous kinematics. Some
complications probably explain why we find rather discrepant BH masses with the
different methods. The stellar kinematics suggest that M_BH = (2.6 +/-
1.1)*10^9 Msun (3 sigma error). The gas kinematics suggests that M_BH ~
3.5*10^8 Msun if the gas is assumed to rotate at the circular velocity in a
thin disk. If the observed velocity dispersion of the gas is assumed to be
gravitational, then M_BH could be as high as ~1.0*10^9 Msun. These different
estimates bracket the value M_BH = (1.1 +/- 0.3)*10^9 Msun predicted by the
M_BH-sigma relation. It will be an important goal for future studies to assess
the reliability of black hole mass determinations with either technique. This
is essential if one wants to interpret the correlation between the BH mass and
other global galaxy parameters (e.g. velocity dispersion) and in particular the
scatter in these correlations (believed to be only ~0.3 dex). [Abridged]Comment: 51 pages, LaTeX with 19 PostScript figures. Revised version, with
three new figures and data tables. To appear in The Astrophysical Journal,
578, 2002 October 2
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