Interstellar Ti II in the Milky Way and Magellanic Clouds

We discuss several sets of Ti II absorption-line data, which probe a variety of interstellar environments in our Galaxy and in the Magellanic Clouds. Comparisons of high-resolution (FWHM ~ 1.3-1.5 km/s) Ti II spectra of Galactic targets with corresponding high-resolution spectra of Na I, K I, and Ca II reveal both similarities and differences in the detailed structure of the absorption-line profiles -- reflecting component-to-component differences in the ionization and depletion behaviour of those species. Moderate-resolution (FWHM ~ 3.4-4.5 km/s) spectra of more heavily reddened Galactic stars provide more extensive information on the titanium depletion in colder, denser clouds -- where more than 99.9 per cent of the Ti may be in the dust phase. Moderate-resolution (FWHM ~ 4.5-8.7 km/s) spectra of stars in the Magellanic Clouds suggest that the titanium depletion is generally much less severe in the LMC and SMC than in our Galaxy [for a given N(H_tot), E(B-V), or molecular fraction f(H_2)] -- providing additional evidence for differences in depletion patterns in those two lower-metallicity galaxies. We briefly discuss possible implications of these results for the interpretation of gas-phase abundances in QSO absorption-line systems and of variations in the D/H ratio in the local Galactic ISM.Comment: 56 pages, 26 figures, accepted to MNRA

Small-scale morphologic properties of martian gullies: insights from analysis of HiRISE images

Abstract not available

OH+ in Diffuse Molecular Clouds

Near ultraviolet observations of OH+ and OH in diffuse molecular clouds reveal a preference for different environments. The dominant absorption feature in OH+ arises from a main component seen in CH+ (that with the highest CH+/CH column density ratio), while OH follows CN absorption. This distinction provides new constraints on OH chemistry in these clouds. Since CH+ detections favor low-density gas with small fractions of molecular hydrogen, this must be true for OH+ as well, confirming OH+ and H2O+ observations with the Herschel Space Telescope. Our observed correspondence indicates that the cosmic ray ionization rate derived from these measurements pertains to mainly atomic gas. The association of OH absorption with gas rich in CN is attributed to the need for high enough density and molecular fraction before detectable amounts are seen. Thus, while OH+ leads to OH production, chemical arguments suggest that their abundances are controlled by different sets of conditions and that they coexist with different sets of observed species. Of particular note is that non-thermal chemistry appears to play a limited role in the synthesis of OH in diffuse molecular clouds.Comment: 15 pages, 4 figures, to appear in ApJ Letter

Diffuse Atomic and Molecular Gas in the Interstellar Medium of M82 toward SN 2014J

We present a comprehensive analysis of interstellar absorption lines seen in moderately-high resolution, high signal-to-noise ratio optical spectra of SN 2014J in M82. Our observations were acquired over the course of six nights, covering the period from ~6 days before to ~30 days after the supernova reached its maximum B-band brightness. We examine complex absorption from Na I, Ca II, K I, Ca I, CH+, CH, and CN, arising primarily from diffuse gas in the interstellar medium (ISM) of M82. We detect Li I absorption over a range in velocity consistent with that exhibited by the strongest Na I and K I components associated with M82; this is the first detection of interstellar Li in a galaxy outside of the Local Group. There are no significant temporal variations in the absorption-line profiles over the 37 days sampled by our observations. The relative abundances of the various interstellar species detected reveal that the ISM of M82 probed by SN 2014J consists of a mixture of diffuse atomic and molecular clouds characterized by a wide range of physical/environmental conditions. Decreasing N(Na I)/N(Ca II) ratios and increasing N(Ca I)/N(K I) ratios with increasing velocity are indicative of reduced depletion in the higher-velocity material. Significant component-to-component scatter in the N(Na I)/N(Ca II) and N(Ca I)/N(Ca II) ratios may be due to variations in the local ionization conditions. An apparent anti-correlation between the N(CH+)/N(CH) and N(Ca I)/N(Ca II) ratios can be understood in terms of an opposite dependence on gas density and radiation field strength, while the overall high CH+ abundance may be indicative of enhanced turbulence in the ISM of M82. The Li abundance also seems to be enhanced in M82, which supports the conclusions of recent gamma-ray emission studies that the cosmic-ray acceleration processes are greatly enhanced in this starburst galaxy.Comment: 32 pages, 6 figures, accepted to ApJ; added table giving single-epoch equivalent widths; improved discussion regarding the lack of temporal variations; improved analysis of the Li I regio

Interstellar absorptions and shocked clouds towards supernova remnant RX J0852.0-4622

We present results of survey of interstellar absorptions towards supernova remnant (SNR) RX J0852.0-4622. The distribution of KI absorbers along the distance of the background stars is indicative of a local region (d<600pc) strongly depopulated by KI line-absorbing clouds. This fact is supported by the behavior of the interstellar extinction. We find four high-velocity CaII components with velocities of >100km/s towards three stars and identify them with shocked clouds of Vela SNR. We reveal and measure acceleration of two shocked clouds at the approaching and receding sides of Vela SNR along the same sight line. The clouds acceleration, velocity, and CaII column density are used to probe cloud parameters. The total hydrogen column density of both accelerating clouds is found to be similar (~6*10^{17} cm$^{-2}$) which indicates that possibly there is a significant amount of small-size clouds in the vicinity of Vela SNR.Comment: accepted in MNRA

Knowledge and Awareness of HPV Vaccine and Acceptability to Vaccinate in Sub-Saharan Africa: A Systematic Review

Objectives: We assessed the knowledge and awareness of cervical cancer, HPV and HPV vaccine, and willingness and acceptability to vaccinate in sub-Saharan African (SSA) countries. We further identified countries that fulfill the two GAVI Alliance eligibility criteria to support nationwide HPV vaccination. Methods: We conducted a systematic review of peer-reviewed studies on the knowledge and awareness of cervical cancer, HPV and HPV vaccine, and willingness and acceptability to vaccinate. Trends in Diphtheria-tetanus-pertussis (DTP3) vaccine coverage in SSA countries from 1990–2011 were extracted from the World Health Organization database. Findings: The review revealed high levels of willingness and acceptability of HPV vaccine but low levels of knowledge and awareness of cervical cancer, HPV or HPV vaccine. We identified only six countries to have met the two GAVI Alliance requirements for supporting introduction of HPV vaccine: 1) the ability to deliver multi-dose vaccines for no less than 50% of the target vaccination cohort in an average size district, and 2) achieving over 70% coverage of DTP3 vaccine nationally. From 2008 through 2011 all SSA countries, with the exception of Mauritania and Nigeria, have reached or maintained DTP3 coverage at 70% or above. Conclusion: There is an urgent need for more education to inform the public about HPV, HPV vaccine, and cervical cancer, particularly to key demographics, (adolescents, parents and healthcare professionals), to leverage high levels of willingness and acceptability of HPV vaccine towards successful implementation of HPV vaccination programs. There is unpreparedness in most SSA countries to roll out national HPV vaccination as per the GAVI Alliance eligibility criteria for supporting introduction of the vaccine. In countries that have met 70% DTP3 coverage, pilot programs need to be rolled out to identify the best practice and strategies for delivering HPV vaccines to adolescents and also to qualify for GAVI Alliance support