[CI], [CII] and CO emission lines as a probe for alpha variations at low and high redshifts

The offsets between the radial velocities of the rotational transitions of carbon monoxide and the fine structure transitions of neutral and singly ionized carbon are used to test the hypothetical variation of the fine structure constant, alpha. From the analysis of the [CI] and [CII] fine structure lines and low J rotational lines of 12CO and 13CO, emitted by the dark cloud L1599B in the Milky Way disk, we find no evidence for fractional changes in alpha at the level of |$\Delta \alpha/\alpha$| < 3*10^-7. For the neighbour galaxy M33 a stringent limit on Delta alpha/alpha is set from observations of three HII zones in [CII] and CO emission lines: |$\Delta \alpha/\alpha$| < 4*10^-7. Five systems over the redshift interval z = 5.7-6.4, showing CO J=6-5, J=7-6 and [CII] emission, yield a limit on |$\Delta \alpha/\alpha$| < 1.3*10^-5. Thus, a combination of the [CI], [CII], and CO emission lines turns out to be a powerful tool for probing the stability of the fundamental physical constants over a wide range of redshifts not accessible to optical spectral measurements.Comment: 10 pages, 3 figures, 5 tables. Accepted for publication in MNRA

The Ratio of Total to Selective Extinction Toward Baade's Window

We measure the ratio of total to selective extinction, R_{VI}=A_V/E(V-I), toward Baade's Window by comparing the VIK colors of 132 Baade's Window G and K giants from Tiede, Frogel, & Terndrup with the solar-neighborhood (V-I),(V-K) relation from Bessell & Brett. We find R_{VI}=2.283 +/- 0.016, and show that our measurement has no significant dependence on stellar type from G0 to K4. Adjusting the Paczynski et al. determination of the centroid of the dereddened Baade's Window clump for this revised value of $R_{VI}$, we find I_{0,RC}=14.43 and (V-I)_{0,RC}=1.058. This implies a distance to the Baade's Window clump of d_{BW} = 8.63 +/- 0.16 kpc, where the error bar takes account of statistical but not systematic uncertainties.Comment: 8 pages, 1 figure, submitted to Ap

Cybercrimes in the aftermath of COVID-19: Present concerns and future directions

Cybercrimes are broadly defined as criminal activities carried out using computers or computer networks. Given the rapid and considerable shifts in Internet use and the impact of the COVID-19 pandemic on cybercrime rates, online behaviours have attracted increased public and policy attention. In this article, we map the landscape of cybercrime in the UK by first reviewing legislation and policy, as well as examine barriers to reporting and address investigative challenges. Given the indisputable rise in cybercrime and its mental health impacts, we propose a four-facet approach for research and practice in this field with an eye to systemic shifts and strategies to combat cybercrime holistically: community alliances and social support, state intervention, and infrastructural sensitivity to user diversity. Lastly, empirical evidence from research guides the design of data-driven technology and provision of advice/interventions to provide a safer digital landscape — hence the importance for more informative research

Spin-Orbit Coupling and Symmetry of the Order Parameter in Strontium Ruthenate

Determination of the orbital symmetry of a state in spin triplet Sr$_2$RuO$_4$ superconductor is a challenge of considerable importance. Most of the experiments show that the chiral state of the $\hat{z} (k_x \pm ik_y)$ type is realized and remains stable on lowering the temperature. Here we have studied the stability of various superconducting states of Sr$_2$RuO$_4$ in the presence of spin-orbit coupling. Numerically we found that the chiral state is never the minimum energy. Alone among the five states studied it has $=0$ and is therefore not affected to linear order in the coupling parameter $\lambda$. We found that stability of the chiral state requires spin dependent pairing interactions. This imposes strong constraint on the pairing mechanism.Comment: 4 pages, 4 figure