Hydrides in Young Stellar Objects: Radiation tracers in a protostar-disk-outflow system

Context: Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims: We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation. Methods: W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (about 2500 s) in 8 spectral regions. Results: The target lines including CH, NH, H3O+, and the new molecules SH+, H2O+, and OH+ are detected. The H2O+ and OH+ J=1-0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H2O+ and OH+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds. Conclusions: The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation.Comment: Astronomy and Astrophysics Letters, in pres

Reversal of infall in SgrB2(M) revealed by Herschel/HIFI observations of HCN lines at THz frequencies

To investigate the accretion and feedback processes in massive star formation, we analyze the shapes of emission lines from hot molecular cores, whose asymmetries trace infall and expansion motions. The high-mass star forming region SgrB2(M) was observed with Herschel/HIFI (HEXOS key project) in various lines of HCN and its isotopologues, complemented by APEX data. The observations are compared to spherically symmetric, centrally heated models with density power-law gradient and different velocity fields (infall or infall+expansion), using the radiative transfer code RATRAN. The HCN line profiles are asymmetric, with the emission peak shifting from blue to red with increasing J and decreasing line opacity (HCN to H$^{13}$CN). This is most evident in the HCN 12--11 line at 1062 GHz. These line shapes are reproduced by a model whose velocity field changes from infall in the outer part to expansion in the inner part. The qualitative reproduction of the HCN lines suggests that infall dominates in the colder, outer regions, but expansion dominates in the warmer, inner regions. We are thus witnessing the onset of feedback in massive star formation, starting to reverse the infall and finally disrupting the whole molecular cloud. To obtain our result, the THz lines uniquely covered by HIFI were critically important.Comment: A&A, HIFI special issue, accepte

Characteristics of the gene pool of spring wheat (<i>Triticum aestivum</i> L.) for resistance to loose smut in the forest-steppe of Western Siberia

Among the many diseases of spring wheat caused by pathogenic fungi, loose smut Ustilago tritici (Pers.) Jens. remains to be a dangerous disease with a wide range of distribution. In fields where there is no control over the emergence and spread of the disease, the yield reduction can be up to 10 %, and in the case of highly susceptible varieties, up to 40–50 %. Taking into account the increasing cost of seed protectants and their environmental damage, the cultivation of varieties resistant to loose smut is still the most affordable way to protect plants, reducing the pesticide load on agrocenoses. The crucial point in breeding for resistance is the use of resistant varieties as parental forms. The aim of our research was to isolate samples of spring wheat that are immune to loose smut against the background of artificial infection of plants with a population specific to the West Siberian region. The article presents the results of long-lasting studies of 350 genotypes of spring wheat of different ecological and geographical origin for resistance to disease. Physiological specialization of races was carried out on the basis of a differentiating set consisting of six varieties of soft wheat and three varieties of durum spring wheat. The obtained results in combination with literature data reveal changes in the racial composition of the pathogen population over the past 30–35 years. Varieties of foreign and domestic selection resistant to the West Siberian population of loose smut have been identified. Based on the analysis of pedigree samples, highly and practically resistant to loose smut, we concluded that in breeding for immunity to U. tritici, the same sources of resistance genes are most often used. Among the gene pool of spring wheat of foreign selection, the largest number of genotypes resistant to loose smut is assigned to the countries of the North American geographical zone (USA, Canada, Mexico). These are largely samples containing Ut1 genes, genes from spring wheat ‘Thatcher’ and its sister line ‘DC II-21-44’. Resistance genes in Russian wheat varieties can be traced from cultivars Beloturka, Poltavka, Selivanovsky Hare (using Saratovskaya 29 and its derivatives), and genes from wheatgrass lines AGIS 1 and Grecum 114

Herschel observations of extra-ordinary sources: Detecting spiral arm clouds by CH absorption lines

We have observed CH absorption lines ($J=3/2, N=1 \leftarrow J=1/2, N=1$) against the continuum source Sgr~B2(M) using the \textit{Herschel}/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31 CH absorption features with different radial velocities and line widths are detected and identified. The narrower line width and lower column density clouds show `spiral arm' cloud characteristics, while the absorption component with the broadest line width and highest column density corresponds to the gas from the Sgr~B2 envelope. The observations show that each `spiral arm' harbors multiple velocity components, indicating that the clouds are not uniform and that they have internal structure. This line-of-sight through almost the entire Galaxy offers unique possibilities to study the basic chemistry of simple molecules in diffuse clouds, as a variety of different cloud classes are sampled simultaneously. We find that the linear relationship between CH and H$_2$ column densities found at lower $A_V$ by UV observations does not continue into the range of higher visual extinction. There, the curve flattens, which probably means that CH is depleted in the denser cores of these clouds.Comment: Accepted for publication in A&A, HIFI Special Issu

Herschel observations of EXtra-Ordinary Sources (HEXOS): detecting spiral arm clouds by CH absorption lines

We have observed CH absorption lines (J = 3/2, N = 1 ← J = 1/2, N = 1) against the continuum source Sgr B2(M) using the Herschel/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31 CH absorption features with different radial velocities and line widths are detected and identified. The narrower line width and lower column density clouds show “spiral arm” cloud characteristics, while the absorption component with the broadest line width and highest column density corresponds to the gas from the Sgr B2 envelope. The observations show that each “spiral arm” harbors multiple velocity components, indicating that the clouds are not uniform and that they have internal structure. This line-of-sight through almost the entire Galaxy offers unique possibilities to study the basic chemistry of simple molecules in diffuse clouds, as a variety of different cloud classes are sampled simultaneously. We find that the linear relationship between CH and H2 column densities found at lower AV by UV observations does not continue into the range of higher visual extinction. There, the curve flattens, which probably means that CH is depleted in the denser cores of these clouds

Characteristics of the gene pool of spring wheat (&lt;i&gt;Triticum aestivum&lt;/i&gt; L.) for resistance to loose smut in the forest-steppe of Western Siberia

Among the many diseases of spring wheat caused by pathogenic fungi, loose smut Ustilago tritici (Pers.) Jens. remains to be a dangerous disease with a wide range of distribution. In fields where there is no control over the emergence and spread of the disease, the yield reduction can be up to 10 %, and in the case of highly susceptible varieties, up to 40–50 %. Taking into account the increasing cost of seed protectants and their environmental damage, the cultivation of varieties resistant to loose smut is still the most affordable way to protect plants, reducing the pesticide load on agrocenoses. The crucial point in breeding for resistance is the use of resistant varieties as parental forms. The aim of our research was to isolate samples of spring wheat that are immune to loose smut against the background of artificial infection of plants with a population specific to the West Siberian region. The article presents the results of long-lasting studies of 350 genotypes of spring wheat of different ecological and geographical origin for resistance to disease. Physiological specialization of races was carried out on the basis of a differentiating set consisting of six varieties of soft wheat and three varieties of durum spring wheat. The obtained results in combination with literature data reveal changes in the racial composition of the pathogen population over the past 30–35 years. Varieties of foreign and domestic selection resistant to the West Siberian population of loose smut have been identified. Based on the analysis of pedigree samples, highly and practically resistant to loose smut, we concluded that in breeding for immunity to U. tritici, the same sources of resistance genes are most often used. Among the gene pool of spring wheat of foreign selection, the largest number of genotypes resistant to loose smut is assigned to the countries of the North American geographical zone (USA, Canada, Mexico). These are largely samples containing Ut1 genes, genes from spring wheat ‘Thatcher’ and its sister line ‘DC II-21-44’. Resistance genes in Russian wheat varieties can be traced from cultivars Beloturka, Poltavka, Selivanovsky Hare (using Saratovskaya 29 and its derivatives), and genes from wheatgrass lines AGIS 1 and Grecum 114.</jats:p

Sensation Seeking, Aggression, and Reckless Behavior in High School Students, College Students, and Adults

Replicating work of Arnett, males reported more frequent Reckless Behavior than females, and 27 high school and 48 college students did not differ in scores on Sensation Seeking or Aggression. As anticipated by Arnett, the 35 adults had significantly lower Sensation Seeking and Aggression scores than the two younger groups and less Reckless Behavior as well. In contrast to Arnett, Reckless Behavior did not rise for college students, and Sensation Seeking, but not Aggression, correlated with Reckless Behavior in all samples. </jats:p