The Hubble Missing Globular Cluster Survey (MGCS) has taken one of the last opportunities to complete the census of Galactic globular clusters (GCs) started by past Hubble Space Telescope (HST) programs, securing high-resolution data for 34 GCs never observed before by HST. The previous papers of the series have highlighted the astrometric and photometric potential of the project by analyzing a subsample of targets. We present, and release to the community, the official astro-photometric catalogs of the MGCS for all GCs imaged by this project. We describe the data reduction using state-of-the-art techniques designed for HST. We discuss the photometric calibration and show, for the first time, the synergy with the Gaia catalog to ensure homogeneous photometry across our data set. We compute artificial-star tests that can be used to assess systematics and the completeness level of our data. We combined HST and Gaia data to refine the absolute PMs of our GCs, reaching a precision $\sim$3 times better than that of Gaia alone. We used these new PMs to update (and to determine for the first time for six systems) the associations between GCs and their putative galaxy progenitors. This work continues decades-long efforts of large Treasury programs in sharing precise and accurate atlases to the community for studying GCs across a wide range of scientific endeavors.
xeno-/exo-/astro -choreoreadings is a postdoctoral artistic research project that explores research questions that reopen site- and place-responsive choreographic practices by expanding the notions of ‘site’ and ‘place’ to outer space. The prefixes in the title refer to planetary conditions to which I do not have direct access. Another key choreographic exploration focuses on embodying hyper-reading and examining the impact of digital reading on embodied artistic practice. Hyper-reading refers to a computer-assisted, screen-based reading practice that has become common in contemporary daily life globally. It connects the reader to the limitless cyberspace. The research project blends these two spatial dimensions, in which the examination of the notions of choreography and choreoreading happen. The research process is multidisciplinary and hybrid in nature, producing artworks, traces, and reflections. The results are presented in this exposition as artworks and as reflections on the choreographic practice that this process has clarified.<style>/* rules to make button only show up in META */.download-accessible { display:none;}.meta-right-col .download-accessible { display: inline-block; padding: 9px; margin-bottom:25px; border: 1px solid black; background-color:white;}</style><a class="download-accessible" href="/profile/download-media?work=4081900&file=4083694" title="This accessible PDF is a derivative of the original which it is meant to support and not replace.">Download Accessible PDF</a></span> keywords: choreoreading, Choreography, artistic research, place-taking, space / place, space and body
We all love the ecstasy that comes with submitting papers to journals or arXiv. Some have described it as yeeting their back-breaking products of labor into the void, wishing they could never deal with them ever again. The very act of yeeting papers onto arXiv contributes to the expansion of the arXiverse; however, we have yet to quantify our contribution to the cause. In this work, I investigate the expansion of the arXiverse using the arXiv astro-ph submission data from 1992 to date. I coin the term "the arXiverse constant", $a_0$, to quantify the rate of expansion of the arXiverse. I find that astro-ph as a whole has a positive $a_0$, but this does not always hold true for the six subcategories of astro-ph. I then investigate the temporal changes in $a_0$ for the astro-ph subcategories and astro-ph as a whole, from which I infer the fate of the arXiverse.
Fabian Schüssler, M. de Bony de Lavergne, A. Kaan Alkan
et al.
In recent decades, astronomy and astrophysics have experienced several fundamental changes. On one hand, there has been a significant increase in the observation of transient phenomena, which are short-lived events such as supernova explosions, fast radio bursts, and gamma-ray bursts. In addition, the detection of a growing number of different cosmic messengers provides researchers with crucial information about these objects. For example, the detection of high-energy neutrinos and gravitational waves regularly complements traditional astronomical observations in the electromagnetic spectrum. This trend is expected to intensify in the coming years with the commissioning of a wide variety of next-generation observatories, which will enable more in-depth studies of the transient sky. To enhance our understanding and optimize the observations of these phenomena, we have developed the Astro-COLIBRI platform. It is freely available to amateur and professional astronomers in the form of a smartphone application (iOS and Android), a web interface, an API, and a chatbot 'Astro-COLIBRI GPT', among many other features. Astro-COLIBRI serves as a central access point for information on astrophysical sources and transient events, allowing a wide network of observers to track and receive real-time alerts. Here we highlight the key features of Astro-COLIBRI, with a particular emphasis on recent innovations. These include a discussion forum that facilitates user interactions and our strengthened collaboration with various networks of amateur astronomers.
The standard model of particle physics describes matter and antimatter as coming from the same fields and this fact has been confirmed experimentally. It is then curious that the observable universe is made of matter and not antimatter. We will first discuss the evidence that we live in a matter-dominated (or matter-antimatter asymmetric) Universe and then proceed to discuss if this can be explained according to our current understanding of the cosmology and particle physics. We will argue that an important process known as baryogenesis to generate a cosmic matter-antimatter asymmetry had to occur before the Universe was a few second old. Then, we will discuss the necessary ingredients for a successful baryogenesis and point out that the current model contains all the ingredients but not in a sufficient amount. Finally, we will discuss possible extensions to the current model which allow successful baryogenesis and how they can be tested experimentally. Interestingly, they might also be connected to other open puzzles in the fundamental physics, like the tiny neutrino mass.
Se presenta una introducción a los fundamentos de la Relatividad General y la noción de Agujeros Negros de una manera elemental, asumiendo conocimientos básicos de Física, y relegando a notas al pie de página aquellas acotaciones técnicas que requieran mayores conocimientos. Se da además una breve introdución histórica del concepto de agujero negro, y se mencionan los notables avances recientes en el campo experimental: la detección en 2015 de ondas gravitacionales en LIGO y las imágenes obtenidas por el Event Horizon Telescope.
Com observações cuidadosas e sistemáticas do céu, há muito tempo o ser humano vem construindo e refinando o seu conhecimento a respeito do Universo e de si mesmo. As grandezas observacionais sobre as quais repousa a astronomia estão sendo, finalmente, abundantemente medidas e com precisões inimagináveis graças à Missão Espacial Gaia da Agência Espacial Europeia. Com seus três data releases (2016, 2018 e 2020/22), temos, hoje, em nossas mãos, dados observacionais em quantidade e com qualidade com as quais até bem pouco tempo nem sonhávamos. Entre eles, a grandeza mais importante de toda a astronomia: a distância de mais de um 1,5 bilhão de estrelas que nos permite dizer onde se encontram, como são e como ''dançam'', iniciando assim, uma nova era no estudo da Galáxia e do Universo. Esses dados, disponibilizados para o mundo todo ao mesmo tempo, representam uma alteração radical na base do conhecimento astronômico e impactam tremendamente a astronomia no sentido mais amplo do termo, por muitos e muitos anos. Colegas de todas as partes do mundo estão mergulhados nesse oceano de posições, movimentos, brilhos, cores, etc, confirmando, revendo e refinando o que sabemos e prestes a enfrentarem, uma vez mais na história, o novo.
Frances M. Skinner, Robert J. Hargreaves, Iouli E. Gordon
The latest version of the HITRAN molecular spectroscopic database, HITRAN2020, has recently been released featuring many updates, including line-by-line broadening parameters (and their temperature dependence) appropriate for the dominant constituents of planetary atmospheres. In this work, line shape codes suitable for calculating microwave spectra have been implemented within the HITRAN Application Programming Interface (HAPI). These new additions allow for spectroscopic calculations of microwave absorbing species pertinent to current and future studies of the atmospheres of Jupiter and Venus, and more generally for the atmospheres of gas giants and rocky planets. The inversion spectrum of the NH$_3$ molecule broadened by H$_2$, He and H$_2$O dominates the microwave region of Jupiter. Whereas for Venus, accurate spectroscopic data of SO$_2$ broadened by CO$_2$ is necessary in order to determine its significance, if any, on the reported detection of PH$_3$ in the Venusian upper cloud deck. Comparisons have been made to available microwave laboratory opacities and the following results illustrate that HITRAN data can be used in conjunction with HAPI to reproduce the existing experimental measurements and provide reliable calculation of planetary opacities. Users should be mindful regarding selection of appropriate parameters in HITRAN and selecting suitable line shape functions in HAPI, depending on the spectral region, target molecular species, as well as ambient chemical and thermodynamic conditions.
The spectral and kinetic characteristics of the fluorescence of the solutions of bovine serum albumin (BSA) and the dyes (N-(p-carboxyphenyl) imide of 4-(dimethylamino) naphthalic acid (CAPIDAN) and Bengal Rose (BR)) in BSA solutions were studied at 3.5 dμ>1 and η < 1. The changes of the characteristics of the stationary fluorescence of the studied dyes at different pH of BSA solutions confirm the mechanisms of the binding between CAPIDAN or BR molecules and protein molecules.
We report on our ongoing efforts to develop, implement, and test VR activities for the introductory astronomy course and laboratory. Specifically, we developed immersive activities for two challenging "3D" concepts: Moon phases, and stellar parallax. For Moon phases, we built a simulation on the Universe Sandbox platform and developed a set of activities that included flying to different locations/viewpoints and moving the Moon by hand. This allowed the students to create and experience the phases and the eclipses from different vantage points, including seeing the phases of the Earth from the Moon. We tested the efficacy of these activities on a large cohort (N=116) of general education astronomy students, drawing on our experience with a previous VR Moon phase exercise (Blanco (2019)). We were able to determine that VRbased techniques perform comparably well against other teaching methods. We also worked with the studentrun VR Club at San Diego State University, using the Unity software engine to create a simulated space environment, where students could kinesthetically explore stellar parallax both by moving themselves and by measuring parallactic motion while traveling in an orbit. The students then derived a quantitative distance estimate using the parallax angle they measured while in the virtual environment. Future plans include an immersive VR activity to demonstrate the Hubble expansion and measure the age of the Universe. These serve as examples of how one develops VR activities from the ground up, with associated pitfalls and tradeoffs. 1. Virtual Reality for the Introductory Astronomy Laboratory Our small group at San Diego State University has been exploring the possible use of Virtual Reality (VR) to provide authentic, student-centered laboratory activities to teach difficult-to-grasp 3-dimensional concepts in general education astronomy lecture and lab classes. The hope is that by putting students in the driver’s seat and allowing them to control their vantage point, they will achieve a deeper understanding of these concepts. Our initial trials comparing VR with other teaching methods for Moon phases and eclipses show promise (Blanco 2019; Welsh 2020). This is in accord with the results of a similar Moon Phases study by Madden (2020). Here we report on a continuation of this work, and on the creation of a new VR laboratory activity on stellar parallax. 2. Moon Phases and Eclipses A number of excellent 2D Moon phase simulators are available online, such as the app provided by the University of Nebraska, Lincoln. We wanted to create a much 1 ar X iv :2 10 9. 01 59 2v 1 [ ph ys ic s. ed -p h] 3 S ep 2 02 1 2 Windmiller, Blanco, and Welsh more immersive experience, with six degrees of freedom (“6-dof”), meaning 3 axes of rotation plus 3 directions of translation. These allow the student to look in any direction, and also change their viewpoint by moving around in a defined space (e.g. walking between the Earth and Moon). We adapted the free VR package Universe Sandbox 2 for this activity. Initially we tried keeping the Sun-Earth-Moon system to an accurate relative scale, but this proved awkward for educational purposes – the angular sizes of the Sun and Moon are too small compared to the full field of view. We therefore created a “closer Moon” to facilitate one’s ability to see Moon’s phase and shadow on the Earth, and to create an eclipse by grabbing this Moon using the HTC Vive’s hand controllers. As described in Blanco (2019), we used a “buddy system” to deploy this immersive activity, where each of a pair of students took turns. While one wore the headset, the other read the exercise instructions, recorded results, and monitored the headset view on a large 2D display. The VR room was located in the campus library (“BuildIT MakerSpace” area) so the students had access to the equipment most of the time. Based on feedback from our initial testing (Blanco 2019), we created a pre-lab introductory video describing the headset and hand controllers. We administered preand post-VR experience quizzes to test students’ understanding, and did the same with a "control" group taught by traditional methods. Assessment methods and results are reported in Welsh (2020); Figure 1 shows an example. In summary, we found that students who participated in the VR activity did at least as well as students who were taught with traditional methods, as found by Madden (2020). Figure 1. The change in quiz score for students who did the Moon VR activity (N = 48) versus a control group (N = 68) taught with traditional methods. See Welsh (2020)
In Italy, INFN coordinates the research in the field of astro-particle physics. The supported experimental activities include the study of the cosmic radiation, the search of gravitational waves, the study of dark universe, general and quantum physics, and the study of the neutrino properties. A rich program of experiments installed on the earth, in the space, and underground or underwater is being supported to provide a possible answer to some of the most relevant open questions of particle physics, astrophysics, and cosmology. A short overview of the ongoing effort is presented.
Abstract. The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.
Background: Coronary artery calcium (CAC) is a powerful novel risk indicator for atherosclerotic cardiovascular disease (ASCVD). Currently, there is no available ASCVD risk prediction tool that integrates traditional risk factors and CAC. Methods: To develop a CAC ASCVD risk tool for younger individuals in the general population, subjects aged 40 to 65 without prior cardiovascular disease from 3 population-based cohorts were included. Cox proportional hazards models were developed incorporating age, sex, systolic blood pressure, total and high-density lipoprotein cholesterol, smoking, diabetes mellitus, hypertension treatment, family history of myocardial infarction, high-sensitivity C-reactive protein, and CAC scores (Astro-CHARM model [Astronaut Cardiovascular Health and Risk Modification]) as dependent variables and ASCVD (nonfatal/fatal myocardial infarction or stroke) as the outcome. Model performance was assessed internally, and validated externally in a fourth cohort. Results: The derivation study comprised 7382 individuals with a mean age 51 years, 45% women, and 55% nonwhite. The median CAC was 0 (25th, 75th [0,9]), and 304 ASCVD events occurred in a median 10.9 years of follow-up. The c-statistic was 0.784 for the risk factor model, and 0.817 for Astro-CHARM (P<0.0001). In comparison with the risk factor model, the Astro-CHARM model resulted in integrated discrimination improvement (0.0252), and net reclassification improvement (0.121; P<0.0001), as well. The Astro-CHARM model demonstrated good discrimination (c=0.78) and calibration (Nam-D’Agostino &khgr;2, 13.2; P=0.16) in the validation cohort (n=2057; 55 events). A mobile application and web-based tool were developed to facilitate clinical application of this tool (www.AstroCHARM.org). Conclusion: The Astro-CHARM tool is the first integrated ASCVD risk calculator to incorporate risk factors, including high-sensitivity C-reactive protein and family history, and CAC data. It improves risk prediction in comparison with traditional risk factor equations and could be useful in risk-based decision making for cardiovascular disease prevention in the middle-aged general population.
Colin S. Wallace, Chase Hatcher, Timothy G. Chambers
et al.
The ground-breaking image of a black hole's event horizon, which captured the public's attention and imagination in April 2019, was captured using the power of interferometry: many separate telescopes working together to observe the cosmos in incredible detail. Many recent astrophysical discoveries that have revolutionized the scientific community's understanding of the cosmos were made by interferometers such as LIGO, ALMA, and the Event Horizon Telescope. Astro 101 instructors who want their students to learn the science behind these discoveries must teach about interferometry. Decades of research show that using active learning strategies can significantly increase students' learning and reduces achievement gaps between different demographic groups over what is achieved from traditional lecture-based instruction. As part of an effort to create active learning materials on interferometry, we developed and tested a new Lecture-Tutorial to help Astro 101 students learn about key properties of astronomical interferometers. This paper describes this new Lecture-Tutorial and presents evidence for its effectiveness from a study conducted with 266 Astro 101 students at the University of North Carolina at Chapel Hill.
Jonathan Langleben, Jonathan Tennyson, Sergei N. Yurchenko
et al.
A rovibronic line list for the ground ($X$ $^3Σ^-$) and first excited ($a$ $^1Δ$) states of phosphinidene, $^{31}$PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data are used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm$^{-1}$. The nuclear Schrödinger is solved using these PECs plus Born-Oppenheimer and spin splitting correction terms. Line intensities and Einstein $A$ coefficients are computed using ab initio Dipole Moment Curves (DMC) $X$-$X$ and $a$-$a$. The resulting LaTY line list, which contains 65055 transitions for 2528 rovibronic states up to 24500 cm$^{-1}$ and $J=80$ is used to simulate spectra in emission and absorption at a range of temperatures. The line list is made available in electronic form at the CDS and ExoMol databases.
Philip S. Cowperthwaite, Hsin-Yu Chen, Ben Margalit
et al.
The blossoming field of joint gravitational wave and electromagnetic (GW-EM) astronomy is one of the most promising in astronomy. The first, and only, joint GW-EM event GW170817 provided remarkable science returns that still continue to this day. Continued growth in this field requires increasing the sample size of joint GW-EM detections. In this white paper, we outline the case for using some percentage of LSST survey time for dedicated target-of-opportunity follow up of GW triggers in order to efficiently and rapidly identify optical counterparts. We show that the timeline for the LSST science survey is well matched to the planned improvements to ground based GW detectors in the next decade. LSST will become particularly crucial in the later half of the 2020s as more and more distant GW sources are detected. Lastly, we highlight some of the key science goals that can be addressed by a large sample of joint GW-EM detections.
Abstract. The hard x-ray imaging spectroscopy system of “Hitomi” x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (1 ′ . 7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, which is composed of four layers of Si and one layer of CdTe semiconductor imagers, and an active shield composed of nine Bi4Ge3O12 scintillators to provide low background. The two HXIs started observation on March 8 and 14, 2016 and were operational until 26 March. Using a Crab observation, 5 to 80 keV energy coverage and good detection efficiency were confirmed. The detector background level of 1 to 3 × 10 − 4 counts s − 1 keV − 1 cm − 2 (in detector geometrical area) at 5 to 80 keV was achieved, by cutting the high-background time-intervals, adopting sophisticated energy-dependent imager layer selection, and baffling of the cosmic x-ray background and active-shielding. This level is among the lowest of detectors working in this energy band. By comparing the effective area and the background, it was shown that the HXI had a sensitivity that is same to that of NuSTAR for point sources and 3 to 4 times better for largely extended diffuse sources.
Abstract. Hitomi (ASTRO-H) was the sixth Japanese x-ray satellite that carried instruments with exquisite energy resolution of <7 eV and broad energy coverage of 0.3 to 600 keV. The Soft Gamma-ray Detector (SGD) was the Hitomi instrument that observed the highest energy band (60 to 600 keV). The SGD design achieves a low background level by combining active shields and Compton cameras where Compton kinematics is utilized to reject backgrounds coming from outside of the field of view. A compact and highly efficient Compton camera is realized using a combination of silicon and cadmium telluride semiconductor sensors with a good energy resolution. Compton kinematics also carries information for gamma-ray polarization, making the SGD an excellent polarimeter. Following several years of development, the satellite was successfully launched on February 17, 2016. After proper functionality of the SGD components were verified, the nominal observation mode was initiated on March 24, 2016. The SGD observed the Crab Nebula for approximately two hours before the spacecraft ceased to function on March 26, 2016. We present concepts of the SGD design followed by detailed description of the instrument and its performance measured on ground and in orbit.