ABSTRACT Interstellar ultraviolet absorption lines provide crucial information about the properties of galactic outflows. In this paper, we augment our previous analysis of the systematic properties ...of starburst-driven galactic outflows by expanding our sample to include a rare population of starbursts with exceptionally high outflow velocities. In principle, these could be a qualitatively different phenomenon from more typical outflows. However, we find that instead these starbursts lie on, or along the extrapolation of, the trends defined by the more typical systems studied previously by us. We exploit the wide dynamic range provided by this new sample to determine scaling relations of outflow velocity with galaxy stellar mass (M*), circular velocity, star formation rate (SFR), SFR/M*, and SFR/area. We argue that these results can be accommodated within the general interpretational framework we previously advocated, in which a population of ambient interstellar or circumgalactic clouds is accelerated by the combined forces of gravity and the momentum flux from the starburst. We show that this simple physical picture is consistent with both the strong cosmological evolution of galactic outflows in typical star-forming galaxies and the paucity of such galaxies with spectra showing inflows. We also present simple parameterizations of these results that can be implemented in theoretical models and numerical simulations of galaxy evolution.
Despite the increasing use of teletherapy, it remains unclear if client outcomes differ between remote and in-person settings and, if they do differ, what factors might contribute to these ...differences. The current study synthesized findings on the comparison between teletherapy and in-person therapy using a meta-analytic approach. All known RCTs comparing teletherapy (telephone and videoconferencing therapy) to in-person therapy were identified via bibliographic database search (PsycINFO, Medline, and Cochrane database), manual searches of previously published meta-analyses, and expert contact. We identified 1,393 studies in the initial search, 20 of which satisfied study inclusion criteria. No significant difference was found between teletherapy and in-person therapy in treatment outcomes at posttreatment (g = −0.043) or follow-up (g = −0.045) or in attrition rates (RR = 1.006). Trainee therapists experienced greater client attrition rates in teletherapy than did licensed therapists. Videoconferencing therapy was at greater risk for client attrition than telephone therapy. Within-group findings showed that teletherapy produced a symptom reduction of a large magnitude at posttreatment (g = 1.026) and follow-up (g = 1.021). These findings provide empirical support for the practice of teletherapy and that client outcomes in teletherapy do not differ from in-person versions of treatments.
Public Health Significance StatementsTeletherapy produces comparable outcome to in-person therapy. Trainee therapists are at greater risk of client dropout in teletherapy than licensed therapists.
We analyse the observed distribution of Eddington ratios (L/LEdd) as a function of supermassive black hole mass for a large sample of nearby galaxies drawn from the Sloan Digital Sky Survey. We ...demonstrate that there are two distinct regimes of black hole growth in nearby galaxies. The first is associated with galaxies with significant star formation M*/star formation rate (SFR) ∼ a Hubble time in their central kiloparsec regions, and is characterized by a broad lognormal distribution of accretion rates peaked at a few per cent of the Eddington limit. In this regime, the Eddington ratio distribution is independent of the mass of the black hole and shows little dependence on the central stellar population of the galaxy. The second regime is associated with galaxies with old central stellar populations (M*/SFR ≫ a Hubble time), and is characterized by a power-law distribution function of Eddington ratios. In this regime, the time-averaged mass accretion rate on to black holes is proportional to the mass of stars in the galaxy bulge, with a constant of proportionality that depends on the mean stellar age of the stars. This result is once again independent of black hole mass. We show that both the slope of the power law and the decrease in the accretion rate on to black holes in old galaxies are consistent with population synthesis model predictions of the decline in stellar mass loss rates as a function of mean stellar age. Our results lead to a very simple picture of black hole growth in the local Universe. If the supply of cold gas in a galaxy bulge is plentiful, the black hole regulates its own growth at a rate that does not further depend on the properties of the interstellar medium. Once the gas runs out, black hole growth is regulated by the rate at which evolved stars lose their mass.
Identifying the population of galaxies that was responsible for the reionization of the universe is a long-standing quest in astronomy. We present a possible local analog that has an escape fraction ...of ionizing flux of 21%. Our detection confirms the existence of gaps in the neutral gas enveloping the starburst region. The candidate contains a massive yet highly compact star-forming region. The gaps are most likely created by the unusually strong winds and intense ionizing radiation produced by this extreme object. Our study also validates the indirect technique of using the residual flux in saturated low-ionization interstellar absorption lines for identifying such leaky galaxies. Because direct detection of ionizing flux is impossible at the epoch of reionization, this represents a highly valuable technique for future studies.
ABSTRACT Using ultraviolet absorption lines, we analyze the systematic properties of the warm ionized phase of starburst-driven winds in a sample of 39 low-redshift objects that spans broad ranges in ...starburst and galaxy properties. Total column densities for the outflows are ∼1021 cm−2. The outflow velocity (vout) correlates only weakly with the galaxy stellar mass ( ), or circular velocity (vcir), but strongly with both SFR and SFR/area. The normalized outflow velocity ( ) correlates well with both SFR/area and SFR/ . The estimated outflow rates of warm ionized gas ( ) are ∼1-4 times the SFR, and the ratio does not correlate with vout. We show that a model of a population of clouds accelerated by the combined forces of gravity and the momentum flux from the starburst matches the data. We find a threshold value for the ratio of the momentum flux supplied by the starburst to the critical momentum flux needed for the wind to overcome gravity acting on the clouds (Rcrit). For 10 (strong-outflows) the outflow's momentum flux is similar to the total momentum flux from the starburst and the outflow velocity exceeds the galaxy escape velocity. Neither of these is the case for the weak outflows ( 10). For the weak-outflows, the data severely disagree with many prescriptions in numerical simulations or semi-analytic models of galaxy evolution. The agreement is better for the strong outflows, and we advocate the use of Rcrit to guide future prescriptions.
We measure the net energy efficiency of supernova (SN) and stellar wind feedback in the starburst galaxy M82 and the degree of mass loading of the hot gas piston driving its superwind by comparing a ...large suite of one and two-dimensional hydrodynamical models to a set of observational constraints derived from hard X-ray observations of the starburst region (the fluxes of the He alpha and Ly alpha -like lines of S, Ar, Ca, and Fe, along with the total diffuse E = 2-8 keV X-ray luminosity). These are the first direct measurements of the feedback efficiency and mass loading of SN-heated and enriched plasma in a starburst galaxy. We consider a broad range of plausible parameters for the M82 starburst, varying the age and mode of star formation, the starburst region size and geometry, and SN metal yields. Over all these varied input parameters all the models that satisfy the existing observational constraints have medium to high thermalization efficiencies (30% <= <= 100%) and the volume-filling wind fluid that flows out of the starburst region is only mildly centrally mass loaded (1.0 <= beta <= 2.8). These results imply a temperature of the plasma within the starburst region in the range 30-80 million Kelvin, a mass-flow rate of the wind fluid out of the starburst region of and a terminal velocity of the wind in the range v {infinity} = 1410 - 2240 km s-1 . This velocity is considerably larger than the escape velocity from M82 (v esc 460 km s-1 ) and the velocity of the H alpha emitting clumps and filaments within M82's wind (v H alpha ~ 600 km s-1 ). Drawing on these results we provide a prescription for implementing starburst-driven superwinds in cosmological models of galaxy formation and evolution that more accurately represents the energetics of the hot metal-enriched phases than the existing recipes do.
We introduce xCOLD GASS, a legacy survey providing a census of molecular gas in the local universe. Building on the original COLD GASS survey, we present here the full sample of 532 galaxies with CO ...(1-0) measurements from the IRAM 30 m telescope. The sample is mass-selected in the redshift interval from the Sloan Digital Sky Survey (SDSS) and therefore representative of the local galaxy population with . The CO (1-0) flux measurements are complemented by observations of the CO (2-1) line with both the IRAM 30 m and APEX telescopes, H i observations from Arecibo, and photometry from SDSS, WISE, and GALEX. Combining the IRAM and APEX data, we find that the ratio of CO (2-1) to CO (1-0) luminosity for integrated measurements is , with no systematic variations across the sample. The CO (1-0) luminosity function is constructed and best fit with a Schechter function with parameters , , and . With the sample now complete down to stellar masses of 109 , we are able to extend our study of gas scaling relations and confirm that both molecular gas fractions ( ) and depletion timescale ( ) vary with specific star formation rate (or offset from the star formation main sequence) much more strongly than they depend on stellar mass. Comparing the xCOLD GASS results with outputs from hydrodynamic and semianalytic models, we highlight the constraining power of cold gas scaling relations on models of galaxy formation.
The source responsible for the reionization of the universe is believed to be the population of star-forming galaxies at z ∼ 6 to 12. The biggest uncertainty concerns the fraction of Lyman-continuum ...photons that actually escape from the galaxies. In recent years, several relatively small samples of "leaky" galaxies have been discovered, and clues have begun to emerge as to both the indirect signposts of leakiness and of the conditions/processes that enable the escape of ionizing radiation. In this paper we present the results of a pilot program to test a new technique for finding leaky galaxies, using the weakness of the S ii nebular emission lines relative to typical star-forming galaxies as evidence that the interstellar medium (ISM) is optically thin to the Lyman continuum. We use the Cosmic Origins Spectrograph on the Hubble Space Telescope to detect significant emerging flux below the Lyman edge in two out of three S ii-weak star-forming galaxies at z ∼ 0.3. We show that these galaxies differ markedly in their properties from the class of leaky "Green-Pea" galaxies at similar redshifts: our sample galaxies are more massive, more metal-rich, and less extreme in terms of their stellar population and the ionization state of the ISM. Like the Green Peas, they have exceptionally high star formation rates per unit area. They also share some properties with the known leaky galaxies at z ∼ 3, but are significantly dustier. Our results validate a new method to identify local laboratories for exploring the processes that made it possible for galaxies to reionize the universe.
Psychotherapy at a Distance Markowitz, John C; Milrod, Barbara; Heckman, Timothy G ...
The American journal of psychiatry,
03/2021, Letnik:
178, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The 2020 COVID-19 pandemic has abruptly overwhelmed normal life. Beyond the fear and fatality of the virus itself comes a likely wave of psychiatric disorders. Simultaneously, social distancing has ...changed overnight how psychiatrists and other mental health professionals must treat patients. Telepsychotherapy, until now a promising but niche treatment, has suddenly become treatment as usual. This article briefly reviews the limited clinical evidence supporting different modes of telepsychotherapy, then focuses on how remote therapy affects clinicians and their patients.
The coronavirus disease (COVID-19) pandemic has resulted in a rapid transition from in-person therapy to teletherapy. This study examined mental health providers' perceptions of the differences ...between in-person therapy and teletherapy in common therapeutic attributes and identified therapist characteristics that predicted differences. A sample of 440 therapists and trainees completed an online survey that assessed their provision of clinical services since the outbreak of COVID-19. Therapists provided ratings for having used 28 therapeutic attributes (e.g., empathy, emotional expression) and skills for in-person therapy and teletherapy. Those attributes were clustered into three factors via exploratory factor analysis (EFA) and confirmatory factor analysis (CFA): common therapeutic skills (e.g., warmth), extra-therapeutic influence (e.g., providing resources), and perceived outcome (e.g., symptom reductions). Therapists perceived poorer common therapeutic skills, decreased outcomes, and reduced extra-therapeutic influence when conducting teletherapy compared to in-person therapy. Therapists who reported poorer common therapeutic skills in teletherapy tended to be male, younger, utilize experience-based and relational therapies, have smaller caseloads, and had little training and no prior experience in teletherapy. Additionally, being male, utilizing experience-based and relational therapies, and having no training in teletherapy were associated with therapists' perception of reduced outcome in teletherapy. More intensive training and support in these attributes/skills are needed to improve therapists' confidence and ability to use therapeutic skills during teletherapy and ultimately improve the quality of psychological services in the era of teletherapy.
Clinical Impact Statement
Question:
How do therapists perceive telepsychology differently from face-to-face therapy during the COVID-19 pandemic?
Findings:
Therapists felt less skilled in most therapeutic attributes when conducting teletherapy compared to face-to-face therapy.
Meaning:
Training and support are needed to improve therapists' abilities to use therapeutic skills in telepsychology, particularly those therapists who have little experience with and training in telepsychology.
Next Steps:
It is important to examine whether and how therapists being less skilled in teletherapy versus face-to-face therapy may result in diminished client outcomes.
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