Abstract. We report the results of an unbiased survey for 6.7 GHz methanol maser emission of a ∼21 deg 2 strip of the Galactic plane carried out with the 32 m Toruń radio telescope. An area at 20• ≤ l ≤ 40• , |b| ≤ 0.• 52 was surveyed in an equilateral triangular grid with a sensitivity limit of about 1.6 Jy. We detected a total of 100 sources, 26 of which are new detections. All the new sources are of moderate intensity and their peak flux densities have median value of 6.5 Jy, i.e. about half that of previously known sources in the sample. About 80% of maser sources have IR counterpart candidates within a 1 radius but not all the IRAS counterparts of methanol masers have colours typical of ultracompact HII regions. An excess of masers unassociated with IR sources occurs at 30• because of incompleteness of IR catalogues due to strong confusion near the tangential region of the spiral arm. Our unbiased survey doubled the number of detections as compared to IRAS-based observations. Within the positional uncertainty of 1 about one third of the methanol sources have radio continuum counterparts at 5 GHz of a flux density greater than 2.5-10 mJy. The distribution of methanol sources appears to be consistent with a clustered mode of formation of massive stars.

A new methodology is given to determine basic parameters of flares from their X-ray light curves. Algorithms are developed from the analysis of small X-ray flares occurring during the deep solar minimum of 2009, between Solar Cycles 23 and 24, observed by the Polish Solar Photometer in X-rays (SphinX) on the Complex Orbital Observations Near-Earth of Activity of the Sun-Photon (CORONAS-Photon) spacecraft. One is a semiautomatic flare detection procedure that gives start, peak, and end times for single ("elementary") flare events under the assumption that the light curve is a simple convolution of a Gaussian and exponential decay functions. More complex flares with multiple peaks can generally be described by a sum of such elementary flares. Flare time profiles in the two energy ranges of SphinX (1.16 -1.51 keV, 1.51 -15 keV) are used to derive temperature and emission measure as a function of time during each flare. The result is a comprehensive catalogue -the SphinX Flare Catalogue -which contains 1600 flares or flare-like events and is made available for general use. The methods described here can be applied to observations made by Geosynchronous Operational Environmental Satellites (GOES), the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and other broad-band spectrometers.

Previous estimates of the solar flare abundances of Si, S, Cl, Ar, and K from the RESIK X-ray crystal spectrometer on board the CORONAS-F spacecraft were made on the assumption of isothermal X-ray emission. We investigate the effect on these estimates by relaxing this assumption and instead determining the differential emission measure (DEM) or thermal structure of the emitting plasma by re-analyzing RESIK data for a GOES class M1.0 flare on 2002 November 14 (SOL2002-11-14T22:26) for which there was good data coverage. The analysis method uses a maximumlikelihood (Withbroe-Sylwester) routine for evaluating the DEM. In a first step, called here AbuOpt, an optimized set of abundances of Si, S, Ar, and K is found that is consistent with the observed spectra. With these abundances, the differential emission measure evolution during the flare is found. The abundance optimization leads to revised abundances of silicon and sulfur in the flare plasma: A(S) = 6.94 ± 0.06 and A(Si) = 7.56 ± 0.08 (on a logarithmic scale with A(H) = 12). Previously determined abundances of Ar, K, and Cl from an isothermal assumption are still the preferred values. During the flare's maximum phase, the X-ray-emitting plasma has a basically two-temperature structure, with the cooler plasma with approximately constant temperature (3-6 MK) and a hotter plasma with temperature 16 − 21 MK. Using imaging data from the RHESSI hard X-ray spacecraft, the emission volume of the hot plasma is deduced from which lower limits of the electron density N e and the thermal content of the plasma are given.

Solar X-ray spectra from the RESIK crystal spectrometer on the CORONAS-F spacecraft (spectral range 3.3 − 6.1 Å) are analyzed for thirty-three flares using a method to derive abundances of Si, S, Ar, and K, emission lines of which feature prominently in the spectra. For each spectrum, the method first optimizes element abundances then derives the differential emission measure as a function of temperature based on a procedure given by Sylwester et al. andWithbroe. This contrasts with our previous analyses of RESIK spectra in which an isothermal assumption was used. The revised abundances (on a logarithmic scale with A(H) = 12) averaged for all the flares in the analysis are A(Si) = 7.53 ± 0.08 (previously 7.89 ± 0.13), A(S) = 6.91 ± 0.07 (7.16 ± 0.17), A(Ar) = 6.47±0.08 (6.45±0.07), and A(K) = 5.73±0.19 (5.86±0.20), with little evidence for time variations of abundances within the evolution of each flare. Our previous estimates of the Ar and K flare abundances are thus confirmed by this analysis but those for Si and S are reduced. This suggests the flare abundances of Si and Ar are very close to the photospheric abundance or solar proxies, while S is significantly less than photospheric and the K abundance is much higher than photospheric. These estimates differ to some extent from those in which a single enhancement factor applies to elements with first ionization potential less than 10 eV.GOES importance levels from B4.6 to X1.5 (for catalog of Level 2 spectra, see http://www.cbk.pan.wroc.pl/experiments/resik/RESIK_Level2/index.html). This period was one of high solar activity, near the maximum of Cycle 23, which has not been exceeded since. The spectral range of RESIK, 3.3 − 6.1 Å, was covered by four channels with incident solar X-rays diffracted by two bent crystals of silicon (Si 111 crystal, 2d = 6.27 Å) and two of quartz (quartz 1010 crystal, 2d = 8.51 Å). Lines due to H-and He-like ions of Si, S, Cl, Ar, and K were included in the range, together with associated dielectronic satellites.The ∼ 20% absolute intensity calibration (Sylwester et al. 2005) allows emitting plasma parameters like temperature and emission measure to be deduced with high accuracy, and the presence of nonthermal electrons. Unlike many previous spectrometers, fluorescence due to the crystal material was either eliminated (for the shorter-wavelength channels 1 and 2) or greatly reduced (for channels 3 and 4) by means of on-board pulse-height analyzers, allowing the solar continuum to be observed.Abundance estimates from most of our previous analyses (see Sylwester et al. 2013, and references therein) were made using an isothermal assumption for the emitting plasma with the temperature assumed from the emission ratio of the two GOES channels. Plots of the estimated fluxes of emission lines from a particular element divided by the GOES emission measure (EM GOES ) against GOES temperature (T GOES ) were found to follow closely the theoretical functional form of G(T e ) with an assumed element abundance. The departure SOL2003-01-27T22:19 C...