Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events

Gamma-Ray Bursts (GRBs) directed at Earth from within a few kpc may have damaged the biosphere, primarily though changes in atmospheric chemistry which admit greatly increased Solar UV. However, GRBs are highly variable in spectrum and duration. Recent observations indicate that short (~0.1 s) burst GRBs, which have harder spectra, may be sufficiently abundant at low redshift that they may offer an additional significant effect. A much longer timescale is associated with shock breakout luminosity observed in the soft X-ray (~10^3 s) and UV (~10^5 s) emission, and radioactive decay gamma-ray line radiation emitted during the light curve phase of supernovae (~10^7 s). Here we generalize our atmospheric computations to include a broad range of peak photon energies and investigate the effect of burst duration while holding total fluence and other parameters constant. The results can be used to estimate the probable impact of various kinds of ionizing events (such as short GRBs, X-ray flashes, supernovae) upon the terrestrial atmosphere. We find that the ultimate intensity of atmospheric effects varies only slightly with burst duration from 10^-1 s to 10^8 s. Therefore, the effect of many astrophysical events causing atmospheric ionization can be approximated without including time development. Detailed modeling requires specification of the season and latitude of the event. Harder photon spectra produce greater atmospheric effects for spectra with peaks up to about 20 MeV, because of greater penetration into the stratosphere.Comment: 30 pages, to be published in ApJ. Replaced for conformity with published version, including correction of minor typos and updated reference

Black Love: On the Colours of Feelings in “Confiteor” by Antoni Szandlerowski

The imagination of Antoni Szandlerowski in his collection of letters to Helena Beatus (Confiteor), his beloved one, is dominated by black. The aim of this article is to show that this colour plays a major role in Confiteor therefore it is used be the author most of the times. When he writes about how pure and beautiful Helena Beatus is, he uses metaphors such as: black dove, black iris, dark cloud, dark corridor. It shows how pessimistic about the future and how guilty about the love he felt Antoni Szandlerowski was. The internal conflict was caused by the will to fulfil as a lover and the duty to continue priestly services. Antoni Szandlerowski is full of doubts. He misses Helena Beatus and feels that he cannot be happy without her. On the other hand, he knows that they cannot make their desire to live side by side real. Since the world is a place of pain and misery where the love cannot thrive due to social norms, lovers can bind together only after death. This way of thinking led Szandlerowski to many neurological disorders, caused nightmares and a painful impression that the whole world around fades away. Szandlerowski uses symbols such as a black dove and a black iris to describe his beloved one and to show the dichotomy of his perception. Therefore love is the source of all the pain and suffering for him

Mistyczne maski zmysłowości - młodopolska twórczość księdza Antoniego Szandlerowskiego

Rozprawa ma za zadanie przeanalizować przy pomocy narzędzi, jakimi są między innymi poetyka siebie i biografizm, twórczość księdza Antoniego Szandlerowskiego (1878-1911) w kontekście jego życia oraz miłości do Heleny Beatus. Składa się z rekonstrukcji biografii autora oraz analizy ,,masek zmysłowości” występujących w jego tekstach. Bogatym źródłem informujący o fantazmatach autora jest intymistyka, a konkretnie zbiór listów miłosnych pod tytułem Confiteor. Praca pokazuje bogactwo symboliczne utworu, stanowiącego swego rodzaju księgę deszyfrującą pozostałe teksty. Ważnym elementem pracy jest analiza dramatów. Pojawia się w nich alter ego autora oraz jego ukochanej, skrywających się pod maskami Ziemica, Bożenny, Judasza czy Marii Magdaleny. Dramat z Maria z Magdali traktować można jako utwór konwersyjny upamiętniający przejście Beatus z wyznania judaistycznego na chrześcijaństwo. Znajdująca się w nim figura Judasza pomaga uzupełnić wiedzę na temat sposobu, w jaki postrzegano tę postać w Młodej Polsce. Dramat ponadto można czytać jako modernistyczną commedia dell’arte. Dramat Paraklet stanowi z kolei pod względem konstrukcji katabazę głównych bohaterów. Wykorzystana została w nim figura Lucyfera, który był bohaterem często inkorporowanym do młodopolskich tekstów – Szandlerowski doskonale wpisuje się w ten trend. Tekst stanowi ponadto przykład młodopolskiego dramatu biblijnego czerpiącego z tradycji romantycznej. Na podstawie dramatu Tryumf udało się zrekonstruować nieznane dotąd fragmenty zaginionej tragedii Samson oraz paszkwilu na kler Elenchus cleri alias choleri. Analizę twórczości Szandlerowskiego uzupełnia rozdział poświęcony wierszom, w których istotnym elementem jest symbolika młodopolska stanowiąca kolejną ,,maskę zmysłowości” autora

The low-temperature energy calibration system for the CUORE bolometer array

The CUORE experiment will search for neutrinoless double beta decay (0nDBD) of 130Te using an array of 988 TeO_2 bolometers operated at 10 mK in the Laboratori Nazionali del Gran Sasso (Italy). The detector is housed in a large cryogen-free cryostat cooled by pulse tubes and a high-power dilution refrigerator. The TeO_2 bolometers measure the event energies, and a precise and reliable energy calibration is critical for the successful identification of candidate 0nDBD and background events. The detector calibration system under development is based on the insertion of 12 gamma-sources that are able to move under their own weight through a set of guide tubes that route them from deployment boxes on the 300K flange down into position in the detector region inside the cryostat. The CUORE experiment poses stringent requirements on the maximum heat load on the cryostat, material radiopurity, contamination risk and the ability to fully retract the sources during normal data taking. Together with the integration into a unique cryostat, this requires careful design and unconventional solutions. We present the design, challenges, and expected performance of this low-temperature energy calibration system.Comment: To be published in the proceedings of the 13th International Workshop on Low Temperature Detectors (LTD), Stanford, CA, July 20-24, 200

Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry

A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV - 1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.Comment: In press: Journal of Cosmology and Astroparticle Physics. 6 figures, 3 tables, two associated data files. Major revisions, including results of a greatly expanded computation, clarification and updated references. In the future we will expand the table to at least EeV levels

Gamma-ray bursts and terrestrial planetary atmospheres

We describe results of modeling the effects on Earth-like planets of long-duration gamma-ray bursts (GRBs) within a few kiloparsecs. A primary effect is generation of nitrogen oxide compounds which deplete ozone. Ozone depletion leads to an increase in solar UVB radiation at the surface, enhancing DNA damage, particularly in marine microorganisms such as phytoplankton. In addition, we expect increased atmospheric opacity due to buildup of nitrogen dioxide produced by the burst and enhanced precipitation of nitric acid. We review here previous work on this subject and discuss recent developments, including further discussion of our estimates of the rates of impacting GRBs and the possible role of short-duration bursts.Comment: 12 pages including 5 figures (4 in color). Added discussion of GRB rates and biological effects. Accepted for publication in New Journal of Physics, for special issue "Focus on Gamma-Ray Bursts

Modeling atmospheric effects of the September 1859 Solar Flare

We have modeled atmospheric effects, especially ozone depletion, due to a solar proton event which probably accompanied the extreme magnetic storm of 1-2 September 1859. We use an inferred proton fluence for this event as estimated from nitrate levels in Greenland ice cores. We present results showing production of odd nitrogen compounds and their impact on ozone. We also compute rainout of nitrate in our model and compare to values from ice core data.Comment: Revised version including improved figures; Accepted for publication in Geophys. Res. Lett, chosen to be highlighted by AG

The First Planets: the Critical Metallicity for Planet Formation

A rapidly growing body of observational results suggests that planet formation takes place preferentially at high metallicity. In the core accretion model of planet formation this is expected because heavy elements are needed to form the dust grains which settle into the midplane of the protoplanetary disk and coagulate to form the planetesimals from which planetary cores are assembled. As well, there is observational evidence that the lifetimes of circumstellar disks are shorter at lower metallicities, likely due to greater susceptibility to photoevaporation. Here we estimate the minimum metallicity for planet formation, by comparing the timescale for dust grain growth and settling to that for disk photoevaporation. For a wide range of circumstellar disk models and dust grain properties, we find that the critical metallicity above which planets can form is a function of the distance r at which the planet orbits its host star. With the iron abundance relative to that of the Sun [Fe/H] as a proxy for the metallicity, we estimate a lower limit for the critical abundance for planet formation of [Fe/H]_crit ~ -1.5 + log(r/1 AU), where an astronomical unit (AU) is the distance between the Earth and the Sun. This prediction is in agreement with the available observational data, and carries implications for the properties of the first planets and for the emergence of life in the early Universe. In particular, it implies that the first Earth-like planets likely formed from circumstellar disks with metallicities Z > 0.1 Z_Sun. If planets are found to orbit stars with metallicities below the critical metallicity, this may be a strong challenge to the core accretion model.Comment: 12 pages, 5 figures; accepted for publication in Ap

Climatic and Biogeochemical Effects of a Galactic Gamma-Ray Burst

It is likely that one or more gamma-ray bursts within our galaxy have strongly irradiated the Earth in the last Gy. This produces significant atmospheric ionization and dissociation, resulting in ozone depletion and DNA-damaging ultraviolet solar flux reaching the surface for up to a decade. Here we show the first detailed computation of two other significant effects. Visible opacity of NO2 is sufficient to reduce solar energy at the surface up to a few percent, with the greatest effect at the poles, which may be sufficient to initiate glaciation. Rainout of dilute nitric acid is could have been important for a burst nearer than our conservative nearest burst. These results support the hypothesis that the characteristics of the late Ordovician mass extinction are consistent with GRB initiation.Comment: 12 pages, 2 figures, in press at Geophysical Research Letters. Minor revisions, including details on falsifying the hypothesi