A search for the signature of microquasars in the cosmic ray iron spectrum measured by TIGER

In a recent paper Heinz and Sunyaev suggest that relativistic jets observed in microquasars might result in narrow features in the energy spectra of heavy cosmic rays with ≈1 to ≈10 GeV/nuc. They further argue that such features might be observable if there has been one or more microquasars nearby within the last few million years. We report preliminary results of a search for evidence of such features using data from a 32-day balloon flight of the Trans-Iron Galactic Element Recorder (TIGER). Although this flight took place near solar maximum, calculations of the broadening effects of solar modulation indicate that a narrow feature of sufficient intensity should still be observable. An energy spectrum for iron with high statistical significance has been derived from ≈100,000 Fe events in the energy range from about 2.5 to 10 GeV/nuc. Although our preliminary results do not reveal any obvious features, we will discuss the possibility of observing such features with TIGER and other instruments.     

The role of drift and convection–diffusion mechanisms in small energy global cosmic ray modulation: Application to the hysteresis phenomenon of proton and alpha particle satellite data

The hysteresis effect for small energies of galactic cosmic rays is due to two effects. The first is the same as for neutron monitor energies – the delay of the interplanetary processes responsible for cosmic ray modulation with respect to the initiating solar processes, according to the effective velocity of solar wind and shock waves propagation. Then, the observed cosmic ray intensity is connected to the solar activity variations during many months before the time of cosmic ray measurement. The second is caused by the time delay of small energy cosmic ray diffusion from the boundary of modulation region to the Earth’s orbit. The model describing the connection between solar activity variation and cosmic ray convection–diffusion global modulation for neutron monitor energies is here developed by taking into account also the time-lag of the small energy particle diffusion in the Heliosphere. We use theoretical results on drifts and analytically approximate the dependences of drifts from tilt angle, and take into account the dependence from the sign of primary particles, and from the sign of polar magnetic field (A > 0 or A < 0). The obtained results are applied on proton and alpha-particle satellite data. We analyze satellite 5-min data of proton fluxes with energies >1 MeV, >2 MeV, >5 MeV, >10 MeV, >30 MeV, >50 MeV, >60 MeV, >100 MeV, and in intervals 10–30 MeV, 30–60 MeV, and 60–100 MeV during January 1986–December 1999. We exclude periods with great cosmic ray increases caused by particle acceleration in solar flare events. Then, we determine monthly averaged fluxes, as well as 5-month and 11-month smoothed data. We analyze also satellite 5-min data on alpha-particle fluxes in the energy intervals 60-160 MeV, 160–260 MeV and 330–500 MeV during January 1986–May 2000. We correct observation data for drifts and then compare with what is expected according to the convection–diffusion mechanism. We assume different dimensions of the modulation region (by the time propagation X₀ of solar wind from the Sun to the boundary of modulation region), for X₀ values from 1 to 60 average months, by one-month steps. For each value of X₀ we determine the correlation coefficient between variations of expected and observed cosmic ray intensities (the estimation of cosmic ray intensities values is given in Section 3 by Eq. (9), and the determination of correlation and regression coefficients in Section 3 by Eq. (8)). The dimension of modulation region is determined by the value of X_0 max, for which the correlation coefficient reaches the maximum value. Then the effective radial diffusion coefficient and residual modulation in small energy region can be estimated.     

Study of >100 GeV electrons with BETS detector using a long duration balloon flight in Antarctica

We have observed cosmic-ray electrons from 10 to 1000 GeV by a long duration balloon flight using Polar Patrol Balloon (PPB) in Antarctica. The observation was carried out for 13 days at an altitude of 35 km in January 2004. The detector is an imaging calorimeter composed of scintillating-fiber belts and plastic scintillators inserted between lead plates. The geometrical factor of detector is about 600 cm²sr and the total thickness of lead absorber is 9 radiation lengths. The performance of the detector has been confirmed by the CERN-SPS beam test and also investigated by Monte-Carlo simulations. New telemetry system using a commercial satellite of iridium, power supply by solar batteries, and automatic level control using CPU have successfully been developed and operated during the flight. We have collected 5.7 × 10³ events over 100 GeV including nearly 100 candidates of primary electrons.     

On the usefulness of atmospheric and oceanic angular momentum in recovering polar motion and gravity field variations in a unified process

Earth rotation parameters (ERPs) are excited by variations in the mass distribution on the Earth’s surface and the exchange of angular momentum between the atmosphere and oceans and the solid Earth. The same mass redistribution causes temporal changes in the gravity field coefficients with the second degree harmonics related to the rotational deformation and hence to changes in the Earth’s inertial tensor. If precise models of the atmospheric and oceanic angular momentum (AM) are available solution for polar motion and degree 2 Stokes harmonics can be unified. In this study we utilize SLR tracking of LAGEOS to compare (i) degree 2 harmonics from ERPs and gravitation, and (ii) LAGEOS excitation functions and geophysical data (mass + motion). Finally, we investigate to what extent a unified approach is possible with current models for AM data and gravity mass change estimated from ERP within orbit determinations.     

On the production of highest energy solar protons at 20 January 2005

On January 20, 2005, 7:02–7:05 UT the Aragats Multidirectional Muon Monitor (AMMM) located at 3200 m a.s.l. registered enhancement of the high energy secondary muon flux (threshold ∼5 GeV). The enhancement, lasting for 3 min, has statistical significance of ∼4σ and is related to the X7.1 flare seen by the GOES, and very fast (>2500 km/s) CME seen by SOHO, and the Ground Level Enhancements (GLE) #69 detected by the world-wide network of neutron monitors and muon detectors. The energetic and temporal characteristics of the muon signal from the AMMM are compared with the characteristics of other monitors located at the Aragats Space-Environmental Center (ASEC) and with other neutron and muon detectors. Since secondary muons with energies >5 GeV are corresponding to solar proton primaries with energies 20–30 GeV we conclude that in the episode of the particle acceleration at 7:02–7:05 UT 20 January 2005 solar protons were accelerated up to energies in excess of 20 GeV.     

The temperature map of the loop and coronal sources of an occulted solar flare

An occulted solar flare occurred at about 06:07 UT on 2002, November 2. The RHESSI X-ray images show two separate parts. The lower part consists of a complete loop and the upper part a coronal source which well extends above the solar limb. The loop source shrank for about 3 min with a speed of ∼24 km s⁻¹ during the early impulsive phase and then expanded at ∼7 km s⁻¹, while the coronal source presented an upward motion at about 6 km s⁻¹. We obtained the temperature map of the loop source from RHESSI image spectrum. The temperature of the loop increases with altitude, indicating that the reconnection X-point of this flare is located above the loop source. However, the apparent coronal source is the top of another independent large-scale loop.     

Development of a 2.8 μm film for scientific balloons

Development of a balloon to fly at higher altitudes is one of the most attractive challenges in scientific balloon technologies. After reaching the highest record setting balloon altitude of 53.0 km using the 3.4 μm film in 2002, we tried to make a thinner balloon film. In 2003, we developed a forming die and an air-ring and succeeded in forming a film with a thickness of 3.0 μm and a width of 220 cm. Using this film, we manufactured a balloon with a volume of 5000 m³ and succeeded in flying the balloon up to an altitude of 46.0 km. We then searched for a good combination of resins to make a thinner and wider film and obtained films with widths of 280 cm, and a thickness of 3.0 μm at first, and then 2.8 μm. In 2004, we performed balloon experiments making a 30,000 m³ balloon with the 3.0 μm film and a 5000 m³ balloon with the 2.8 μm film. Both balloons were well manufactured and reached the highest altitudes of 50.7 and 42.6 km, respectively.     

Launching of a 500,000 cubic meter balloon with the semi-dynamic launching method

Launching a large balloon in a limited launching field is a long standing problem in Japan. The largest balloon ever launched successfully was 200,000 m³ in volume. It was launched in 1973. A larger balloon with a volume of 500,000 m³ was tried later, but it burst during the ascending phase. For launching balloons with a large lift exceeding 500 kg, the conventional static launching method had the most serious problem with possible damage to the polyethylene film of the balloon caused by the holding mechanism. After that, we had developed a new static launching method to launch balloons with a total lift of 1.0 ton. For launching a large balloon with a total lift above 1.5 ton, the new static launching method had a weak point in that if there was an air bubble in the folded part of the balloon, it may puncture the balloon as it is pushed by a spool. To avoid this problem, we developed a semi-dynamic launching method in 1999 using a launcher fixed to the ground leaving a freedom of rotation around the vertical axis. We have launched some balloons using the method and have gradually enriched our experience in using this system.In 2003, we successfully launched a balloon with a volume of 500,000 m³ by using the method. This balloon was made of polyethylene films with a thickness of 20 μm and it is the largest balloon ever launched in Japan.     

On long-term changes of electron density in the upper mesosphere

Recent review study done jointly by 19 experts of 17 institutes shows zero trend of temperature in the upper mesosphere. In the light of this latest development, we have examined the long-term changes in electron density, [e], in this region. The study has been concentrated at 80 km. At this altitude, electrons are mainly produced by the interaction of nitric oxide, NO, by solar Ly-α. Any long-term change in this flux will affect trend of [e]. Considering this flux proportional to 10.7 cm solar flux, analysis of available 10.7 cm solar flux data from 1948 to 2003 has been made. A decreasing trend up to about 1970 and then an increasing trend are found. The over-all increasing trend of Ly-α flux during the past five decades is ∼0.17% per year. This increase also gives a ∼0.17% increasing trend per year in [e]. This non-anthropogenic increase is much less compared to the observed increase in [e] which is reported to be >0.7% per year. The observed increase in [e] of this magnitude will then, predominantly, be due to the anthropogenic effect. In zero trend in temperature, significant change in electron loss coefficient, α_eff, and [NO] are unlikely to take place to cause a significant change in [e]. The increase in [e] > 0.7% per year then can be explained by considering a decreasing trend in [O₂].     

Scientific ballooning in Japan – An over view of recent activities

Current status of scientific ballooning in Japan is reviewed. First, I describe successful application of balloon technologies to construct a vessel of transparent plastic film, to contain about 1000 tons of liquid scintillator in Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND). KamLAND is a project to study neutrino oscillation phenomena, by detecting anti-neutrinos produced in distant nuclear reactors. Next, I describe high altitude balloons developed by the ISAS balloon group. They developed balloons made from ultra-thin polyethylene film, producing a balloon of volume 60,000 m³ which successfully reached an altitude of 53 km in 2002. This is a world record, the greatest altitude that a balloon has ever achieved. ISAS is applying further effort to develop balloons with even thinner films, to achieve a higher altitude than 53 km. Other recent activities by the ISAS balloon group are briefly described.I also review scientific ballooning projects now operating in Japan, particularly focusing on the Balloon-Borne Experiment with a Superconducting Spectrometer (BESS) program. This is a US–Japan collaborative program that has carried out very precise measurements of antiprotons, protons and other components in primary cosmic rays, as well as measuring the fluxes of atmospheric muons and other components. The results of these observations give us important information to improve our understanding of the production mechanism of antiprotons observed in the primary cosmic rays. The data are also important for analysis of atmospheric neutrino events observed by Super-Kamiokande and other ground-based neutrino detectors. Future prospects of BESS and other balloon-borne cosmic-ray research programs are also presented.     

Supernova remnant 1987A: The latest report from the Chandra X-ray Observatory

We continue monitoring supernova remnant (SNR) 1987A with the Chandra X-ray Observatory. As of 2004 January, bright X-ray spots in the northwest and the southwest are now evident in addition to the bright eastern ring. The overall X-ray spectrum, since 2002 December, can be described by a planar shock with an electron temperature of ∼2.1 keV. The soft X-ray flux is now 8 × 10⁻¹³ ergs cm⁻² s⁻¹, which is about five times higher than four years ago. This flux increase rate is consistent with our prediction based on an exponential density distribution along the radius of the SNR between the HII region and the inner ring. We still have no direct evidence of a central point source, and place an upper limit of L_X = 1.3 × 10³⁴ ergs s⁻¹ on the 3–10 keV band X-ray luminosity.     

Possible DC electric field in the ionosphere related to seismicity

This paper presents the method for calculation of DC electric field in the atmosphere and the ionosphere generated by model distribution of external electric current in the lower atmosphere. Appearance of such current is associated with enhancement of seismic activity that is accompanied by emanation of soil gases into the atmosphere. These gases transfer positive and negative charged aerosols. Atmospheric convection of charged aerosols forms external electric current, which works as a source of conductivity current in the atmosphere–ionosphere electric circuit. It is shown that DC electric field generated in the ionosphere by this current reaches up to 10 mV/m, while the long-term vertical electric field disturbances excited near the Earth surface do not exceed 100 V/m. Such limitation of the near-ground field is caused by the formation of potential barrier for charged particles at the Earth surface in a process of their transport from soil to atmosphere.     

Modeling of effect of polarization on UV sky radiance during twilight

The spatial distribution of the vector of the Stokes parameters characterizing the radiance intensity and the radiance polarization describes the radiation field in the atmosphere. A simplified treatment of light as the scalar has only restricted application. A few studies compared previously results of the vector and scalar radiative transfer models and showed that scalar models are in error by up to 10% for many cases. Though several observational conditions were exploited, an effect of polarization on modeling of UV radiance has not been investigated yet for twilight. The paper presents a preliminary study of modeled UV radiance during twilight taking into account polarization. The intensity and the degree of linear polarization of the scattered UV radiance for two cases of the ground-based observations are discussed. In the first case, radiation incoming from the zenith for the solar zenith angles (SZA) from 90° to 98° is under investigation. Radiation in the solar principal plane for the beginning of twilight (SZA = 90.1°) was calculated in the second case. The study showed that the UV radiation field in the twilight atmosphere can be handled correctly only using the vector theory. The errors of scalar radiative transfer strongly depend on wavelength, line of an observation and solar position. The revealed distortion of the zenith radiance caused by using of the scalar approximation reaches maximum of 15% at 340 nm for the solar zenith angle (SZA) equal to 98°. The shorter wavelengths have the smaller errors, about 5% at 305 nm for SZA = 98°, due to the larger part of the single scattered radiance. The error of the scalar modeling may be as large as −17% for radiance incoming from the horizon for SZA = 90.1°. Scalar radiative transfer models underestimate the integral intensity in the principal plane up to 3–4% ± 0.5% at SZA = 90.1° for wavelengths from 320 to 340 nm. This should be taken into account in problems of radiative budget estimation and remote sensing of the atmosphere exploiting the twilight period.     

OPTIS – A Satellite test of Special and General Relativity

OPTIS has been proposed as a small satellite platform in a high elliptical orbit (apogee 40,000 km, perigee 10,000 km) and is designed for high precision tests of foundations of Special and General Relativity. The experimental set-up consists of two ultrastable Nd:YAG lasers, three crossed optical resonators (monolithic cavities), an ensemble of atomic clocks, an optical comb generator, laser tracking devices and a drag-free control system. OPTIS enables improved tests of (1) the isotropy and (2) constancy of the speed of light, (3) special relativistic time dilation, (4) the universality of the gravitational redshift by comparison of various clocks, can measure (5) the absolute value of the gravitational redshift, (6) the Lense–Thirring effect and (7) the perigee advance and (8) can make a test of a hypothetical Yukawa part in the gravitational potential. To avoid any influence from atmospheric drag, solar radiation, or Earth albedo, the satellite needs drag-free control to depress the residual acceleration down to 10⁻¹⁴ m/s² in the frequency range between 10⁻² and 10⁻³ Hz. Precise thermal control must be used to stabilize the cavity temperature to within one part in 10⁷ at time scales of 100 s and to one part in 10⁵ on the orbit time scale.     

Hypervelocity impacts on HST solar arrays and the debris and meteoroids population

Accurate debris and meteoroid flux models are crucial for the design of manned and unmanned space missions. For the most abundant particle sizes smaller than a few millimetres, knowledge of the populations can only be gained from in situ detectors or the analysis of retrieved space hardware. The measurement of impact flux from exposed surfaces improves with increased surface area and exposure time.A post-flight impact investigation was initiated by the European Space Agency to record and analyse the impact fluxes and any potential resulting damage on the two flexible solar arrays of the Hubble Space Telescope. The arrays were deployed during the first Hubble Space Telescope servicing mission in December 1993 and retrieved in March 2002. They have a total exposed surface area of roughly 120 m², including 42 m² covered with solar cells. This new Hubble post-flight impact study follows a similar activity undertaken after the retrieval of one of the first solar arrays, in 1993. The earlier study provided the first opportunity for a numerical survey of damage to exposed surfaces from more than 600 km altitude, and of impacts from particles larger than 1 mm. The results have proven very valuable in validation of important flux model regimes. The second set of Hubble solar arrays has again provided an unrivalled opportunity to measure the meteoroid and debris environment, now sampled during a long interval in low Earth orbit, and to identify changes in the space debris environment since the previous survey. The retrieved solar array wings exhibit thousands of craters, many of which are visible to the naked eye. A few hundred impacts have completely penetrated the 0.7 mm thick array. The largest impact features are about 7–8 mm in diameter. The cover glass of the solar cells is particularly well suited to the recognition of small impact features by optical and electron microscopy. In this paper, we present the first results of the impact survey. Data upon the abundance of craters of specific measured size ranges are plotted as cumulative flux curves, and compared to the results of model predictions. The most significant change to the particle flux since 1993 is a decrease in the small debris population.     

On the Stark broadening of the Re II spectral lines

Stark broadening parameters - full widths at half maximum (FWHM) and shifts for 11 Re II lines have been calculated. The plasma parameters used were electron density of ${10}^{17}$ cm^?3 and temperature from 5 000 K to 80 000 K. Calculations were performed using the simplified modified semiempirical (SMSE) approach and compared with calculations by Cowley’s approximative Stark broadening formula at 10000 K, usefull in spectrum synthesis. The results have also been considered in the atmosphere model of A type star and for DB white dwarfs.     

Reconstruction of solar UV irradiance

Understanding solar influence on the Earth’s climate requires a reconstruction of solar irradiance for the pre-satellite period. Considerable advances have been made in modelling the irradiance variations at wavelengths longer than 200 nm. At shorter wavelengths, however, the LTE approximation usually taken in such models fails, which makes a reconstruction of the solar UV irradiance a rather intricate problem. We choose an alternative approach and use the observed SUSIM UV spectra to extrapolate available models to shorter wavelengths.     

The energy spectra of protons and helium measured with the ATIC experiment

The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment is designed to investigate the composition and energy spectra of cosmic rays at the highest energies currently accessible by direct measurements, i.e., the region up to 100 TeV. The instrument consists of a silicon matrix for charge measurement, a graphite target (0.75 nuclear interaction length) to induce hadronic interactions, three layers of scintillator strip hodoscopes for triggering and trajectory reconstruction, and a Bismuth Germanate (BGO) crystal calorimeter (18 radiation lengths) to measure particle energies. ATIC has had two successful Long Duration Balloon (LDB) flights from McMurdo, Antarctica: one from 12/28/00 to 01/13/01 and the other from 12/29/02 to 01/18/03. We present the energy spectra of protons and helium extracted from the first flight, over the energy range from 100 GeV to 100 TeV, and compare them with the results from other experiments at both the lower and higher energies. ATIC-1 results do not indicate significant differences in spectral shape between protons and helium over the investigated energy range.     

XMM-Newton observations of the Mouse,SLX 1744–299 and SLX 1744–300

We observed the radio and X-ray source G359.23–0.82, also known as “the Mouse”, with XMM-Newton. The X-ray image of this object shows a point-like source at the Mouse’s “head”, accompanied by a “tail” that extends for about 40″ westward. The morphology is consistent with that observed recently with Chandra [Gaensler, B.M., van der Swaluw, E., Camilo, F., et al. The Mouse that soared: high resolution X-ray imaging of the pulsar-powered bow shock G359.23–0.82, ApJ 616, 383–402, 2004]. The spectrum of the head can be described by a power-law model with a photon index Γ ≃ 1.9. These results confirm that the Mouse is a bow-shock pulsar wind nebula (PWN) powered by PSR J1747–2958. We found that the hydrogen column density toward the Mouse, N_H = (2.60 ± 0.09) × 10²² cm⁻², is 20%–40% lower than those toward two serendipitously detected X-ray bursters, SLX 1744–299 and SLX 1744–300. At a plausible distance of 5 kpc, the X-ray luminosity of the Mouse, L(0.5–10 keV) = 3.7 × 10³⁴ erg s⁻¹, is 1.5% of the pulsar’s spin-down luminosity. We detected a Type I X-ray burst from SLX 1744–300 and found a possible decrease of N_H and persistent luminosity for this source, in comparison with those observed with ROSAT in 1992.     

The Carrington event: Possible doses to crews in space from a comparable event

Recent ice core analyses suggest that the Carrington event of 1859 may have been the largest solar energetic particle event in the past several hundred years. Previous analyses of potential doses to humans and electronics from such an event suggested that a Carrington-like event, with a hard spectrum similar to that of the event of September 1989 could be catastrophic. Subsequent analyses of the ¹⁰Be concentration in the ice core data suggest that the spectral hardness of the Carrington event was softer and similar to the August 1972 event. In this work we review the earlier estimates of doses from a Carrington event, and present updated dose estimates for deep space crews and electronics using the Carrington event proton fluence ⩾30 MeV in combination with an event spectrum similar to that of the August 1972 event. Potential ramifications of these doses for humans and electronics on deep space missions are discussed.