Sco X-1: The Evolution and Nature of the Twin Compact Radio Lobes

The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are radio lobes generated by the disruption of energy flow in a twin-beam from the binary system. The average lifetime of a lobe-pair, the space motion of the lobes and the measured energy flow in the beam are discussed in arXiv:astro-ph/0104325. The lobe has a flux density that is variable over a time-scale of one hour, a measured minimum size of 1 mas (2.8 au), and is extended perpendicular to its motion. This short electron radiative lifetime may be caused by synchrotron losses if the lobe magnetic field is 300 G, or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a steepening radio spectrum, perhaps related to the characteristics of the beam energy flow. The radio morphology for Sco X-1 is more simple than for most other Galactic jet sources. The lobes of Sco X-1 are similar to hot-spots found in many extragalactic double sources. Scaling the phenomena observed in Sco X-1 to extragalactic sources implies hot-spot variability time-scales of 10^4 yr and hot-spot lifetimes of 10^5 yr. The recurrent formation of lobes in Sco X-1 probably does not occur for extragalactic radio sources.Comment: 22 pages of text + 16 figures. ApJ, in pres

The Hardness-Intensity Diagram of Cygnus X-3: Revisiting the Radio/X-Ray States

Cygnus X-3 is one of the brightest X-ray and radio sources in the Galaxy, and is well known for its erratic behaviour in X-rays as well as in the radio, occasionally producing major radio flares associated with relativistic ejections. However, even after many years of observations in various wavelength bands Cyg X-3 still eludes clear physical understanding. Studying different emission bands simultaneously in microquasars has proved to be a fruitful approach towards understanding these systems, especially by shedding light on the accretion disc/jet connection. We continue this legacy by constructing a hardness-intensity diagram (HID) from archival Rossi X-ray Timing Explorer data and linking simultaneous radio observations to it. We find that surprisingly Cyg X-3 sketches a similar shape in the HID to that seen in other transient black hole X-ray binaries during outburst but with distinct differences. Together with the results of this analysis and previous studies of Cyg X-3 we conclude that the X-ray states can be assigned to six distinct states. This categorization relies heavily on the simultaneous radio observations and we identify one new X-ray state, the hypersoft state, similar to the ultrasoft state, which is associated to the quenched radio state during which there is no or very faint radio emission. Recent observations of GeV flux observed from Cyg X-3 (Tavani et al. 2009; Fermi LAT Collaboration et al. 2009) during a soft X-ray and/or radio quenched state at the onset of a major radio flare hint that a very energetic process is at work during this time, which is also when the hypersoft X-ray state is observed. In addition, Cyg X-3 shows flaring with a wide range of hardness.Comment: 17 pages, 9 figures, accepted for publication in MNRA

Dissociating the effects of alternative early-life feeding schedules on the development of adult depression-like phenotypes

Neville, V., Andrews, C., Nettle, D. and M. Bateson (2017). Dissociating the effects of alternative early-life feeding schedules on the development of adult depression-like phenotypes. Scientific Reports 7: 14832

Oscillatory magnetic brain activity is related to dissociative symptoms and childhood adversities - A study in women with multiple trauma

BackgroundIndividuals with trauma-related disorders are complex and heterogeneous; part of this complexity derives from additional psychopathology like dissociation as well as environmental adversities such as traumatic stress, experienced throughout the lifespan. Understanding the neurophysiological abnormalities in Post-traumatic stress disorder (PTSD) requires a simultaneous consideration of these factors.MethodsResting state magnetoencephalography (MEG) recordings were obtained from 41 women with PTSD and comorbid depressive symptoms, and 16 healthy women. Oscillatory brain activity was extracted for five frequency bands and 11 source locations, and analyzed in relation to shutdown dissociation and adversity-related measures.ResultsDissociative symptoms were related to increased delta and lowered beta power. Adversity-related measures modulated theta and alpha oscillatory power (in particular childhood sexual abuse) and differed between patients and controls.LimitationsFindings are based on women with comorbid depressive symptoms and therefore may not be applicable for men or groups with other clinical profiles. In respect to childhood adversities, we had no reliable source for the early infancy.ConclusionTrauma-related abnormalities in neural organization vary with both exposure to adversities as well as their potential to evoke ongoing shutdown responses

Measuring types and timing of childhood maltreatment : The psychometric properties of the KERF-40+

Childhood maltreatment, specifically during sensitive developmental periods, is a major risk factor for poor physical and mental health. Despite its enormous clinical relevance, there is still a lack of scales measuring different types, timing, and duration of childhood maltreatment. The current study sought to validate and determine the psychometric properties of the brief German version of the Maltreatment and Abuse Chronology of Exposure (MACE) scale, the KERF-40. The KERF-40 was administered as an interview (i.e., KERF-40-I) to 287 adult participants with and without mental disorders. Based on item response theory, items of the KERF-40-I were assigned to different types of maltreatment, resulting in a scaled version, the KERF-40+. Test-retest reliability was assessed in a small subsample (n = 14). Convergent and relative predictive validity were measured with correlations of the KERF-40+ and the Childhood Trauma Questionnaire (CTQ) as well as self-report measures of general and trauma-related psychopathology. Rasch analysis and fit statistics yielded a 49-item version, encompassing ten different types of maltreatment. The test-retest reliability of the KERF-40+ was shown to be acceptable to excellent for almost all global and subscale scores (.74 ≤ ρ ≤ 1.00), with the exception of the subscale emotional neglect (ρ = .55). Convergent validity with the CTQ was confirmed for both KERF-40+ global scores (.72 ≤ r ≤ .87) and corresponding subscale scores (.56 ≤ r ≤ .78). Relative predictive validity was reflected by significant small-to-moderate correlations between KERF-40+ global scores and indices of general and trauma-related psychopathology (.24 ≤ r ≤ .45). Taken together, the KERF-40+ appears to be suited for clinicians and researchers interested in retrospectively assessing different types, timing, and duration of childhood maltreatment experiences during sensitive periods in adults.publishe

Simultaneous and quasi-simultaneous observations of the continuum emission of the quasar 3C 273 from radio to γ-ray energies

From June 15-28, 1991 the Compton Gamma-Ray Observatory (CGRO) observed the radio-loud quasar 3C 273. All four CGRO instruments detected radiation from this quasar in their relevant energy ranges (from 20keV to 5GeV). Simultaneous and quasi-simultaneous observations by instruments sensitive at other wavelengths have also been performed. The data from all these observations, spanning the frequency range from 5.10^9^Hz to 8.5.10^24^Hz, were collected and analysed. Details of the observations and an overall energy-density spectrum are presented. This spectrum shows three maxima, one in the infrared (IR), one in the UV and another one at low-energy γ-rays, the latter two having nearly the same strength of 3.1.10^46^erg/(s frequency decade) and 2.7.10^46^erg/(s frequency decade), respectively. At low-energy γ-rays a break around 1MeV (=2.418.10^20^Hz) in the energy-density spectrum is evident. The change of the spectral index between X- and γ-rays is ~0.8. The implications of these simultaneous and quasi-simultaneous observations on some theoretical models are discussed