arXiv subjects

Xiaoming Jiang

Publications and source records attributed to Xiaoming Jiang.

7 recordsLinked to original sources

arXiv2025

Estimating the Mass Escaping Rates of Radius-valley-spanning Planets in the TOI-431 System via X-Ray and Ultraviolet Evaporation

TOI-431 system has 3 close-in exoplanets, which gives an ideal lab to study gas escape. In this study, we measure the XUV luminosity for TOI-431 with XMM-Newton/EPIC-pn and OM data, then calculate the fluxes for the planets in the system. We find that, TOI-431 b's $\rm F_{XUV,b}=$$70286^{+12060}_{-2611}$$\rm \ erg\ cm^{-2}s^{-1}$ is 75 times of TOI-431 d $\rm F_{XUV,d}=$$935^{+160}_{-35}$$\rm \ erg\ cm^{-2}s^{-1}$. Adopting the energy limit method and hydrodynamic code $ATES$ with a set of He/H ratios, we obtain the mass-loss rates of $10^{10.51^{+0.07}_{-0.02}}$ g s$^{-1}$ for TOI-431 b, $10^{9.14^{+0.07}_{-0.02}}$ and $10^{9.84\sim 9.94}$ g s$^{-1}$ for TOI-431 d. We predict the $2.93\sim 7.91 \%$ H I Ly$α$ and $0.19\sim 10.65\%$ He I triplet absorption depths for TOI-431 d, thus its gas escaping is detectable in principle. For both TOI-431 b and d, we select similar planets from the New Generation Planetary Population Synthesis (NGPPS) data. Then show that considering the mass-loss rates, TOI-431 b should be a naked solid planet, and TOI-431 d will likely maintain its gas envelope until the host star dies. According to the formation and evolution tracks, we find that TOI-431 b's potential birthplace (0.1-2 AU) should be inner than TOI-431 d (2-12 AU). Our results are consistent with the interpretation of the radius valley being caused by atmospheric escape. The intrinsic reason may be their birthplace, which will determine how close they can migrate to the host star, then lose mass and result in the Fulton gap.

astro-ph.EP↗

arXiv2023

Message in a Bottle -- An Update to the Golden Record

In this first part of our series, we delve into the foundational aspects of the "Message in a Bottle" (henceforth referred to as MIAB). This study stands as a continuation of the legacy set by the Voyager Golden Records launched aboard Voyager 1 and 2 in 1977, which aimed to communicate with intelligent species beyond our world. These Records continue to serve not only as a snapshot of Earth and humanity but also carry forth our desire for establishing contact with advanced alien civilizations. Given the absence of mutually understood signs, symbols, and semiotic conventions, MIAB, like its predecessor, seeks to use scientific methods to design an innovative means of communication encapsulating the story of humanity. Our aim is to convey our collective knowledge, feelings, innovations, and aspirations in a manner that offers a universal, yet contextual understanding of human society, the evolution of life on Earth, and our hopes and concerns for the future. Through this time and space traveling capsule, we also strive to inspire and unify current and future generations to celebrate and safeguard our shared human experience.

cs.CY↗

arXiv2022

A Beacon in the Galaxy: Updated Arecibo Message for Potential FAST and SETI Projects

An updated, binary-coded message has been developed for transmission to extraterrestrial intelligences in the Milky Way galaxy. The proposed message includes basic mathematical and physical concepts to establish a universal means of communication followed by information on the biochemical composition of life on Earth, the Solar System's time-stamped position in the Milky Way relative to known globular clusters, as well as digitized depictions of the Solar System, and Earth's surface. The message concludes with digitized images of the human form, along with an invitation for any receiving intelligences to respond. Calculation of the optimal timing during a given calendar year is specified for potential future transmission from both the Five-hundred-meter Aperture Spherical radio Telescope in China and the SETI Institute's Allen Telescope Array in northern California to a selected region of the Milky Way which has been proposed as the most likely for life to have developed. These powerful new beacons, the successors to the Arecibo radio telescope which transmitted the 1974 message upon which this expanded communication is in part based, can carry forward Arecibo's legacy into the 21st century with this equally well-constructed communication from Earth's technological civilization.

physics.pop-ph↗

arXiv2020

Dimer rattling mode induced low thermal conductivity in an excellent acoustic conductor

A solid with larger sound speeds exhibits higher lattice thermal conductivity (k_{lat}). Diamond is a prominent instance where its mean sound speed is 14400 m s-1 and k_{lat} is 2300 W m-1 K-1. Here, we report an extreme exception that CuP2 has quite large mean sound speeds of 4155 m s-1, comparable to GaAs, but the single crystals show a very low lattice thermal conductivity of about 4 W m-1 K-1 at room temperature, one order of magnitude smaller than GaAs. To understand such a puzzling thermal transport behavior, we have thoroughly investigated the atomic structure and lattice dynamics by combining neutron scattering techniques with first-principles simulations. Cu atoms form dimers sandwiched in between the layered P atomic networks and the dimers vibrate as a rattling mode with frequency around 11 meV. This mode is manifested to be remarkably anharmonic and strongly scatters acoustic phonons to achieve the low k_{lat}. Such a dimer rattling behavior in layered structures might offer an unprecedented strategy for suppressing thermal conduction without involving atomic disorder.

cond-mat.mtrl-sci↗

arXiv2017

Out-of-plane easy-axis in thin films of diluted magnetic semiconductor Ba1-xKx(Zn1-yMny)2As2

Single-phased, single-oriented thin films of Mn-doped ZnAs-based diluted magnetic semiconductor (DMS) Ba1-xKx(Zn1-yMny)2As2 (x = 0.03, 0.08; y = 0.15) have been deposited on Si, SrTiO3, LaAlO3, (La,Sr)(Al,Ta)O3, and MgAl2O4 substrates, respectively. Utilizing a combined synthesis and characterization system excluding the air and further optimizing the deposition parameters, high-quality thin films could be obtained and be measured showing that they can keep inactive-in-air up to more than 90 hours characterized by electrical transport measurements. In comparison with films of x = 0.03 which possess relatively higher resistivity, weaker magnetic performances, and larger energy gap, thin films of x = 0.08 show better electrical and magnetic performances. Strong magnetic anisotropy was found in films of x = 0.08 grown on (La,Sr)(Al,Ta)O3 substrate with their magnetic polarization aligned almost solely on the film growth direction.

cond-mat.mtrl-sci↗

arXiv2016

The most-luminous heavily-obscured quasars have a high merger fraction: morphological study of WISE-selected hot dust-obscured galaxies

Previous studies have shown that WISE-selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick AGNs. High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at $z\sim3$ using Hubble Space Telescope/WFC3 imaging. We find that Hot DOGs have a high merger fraction ($62\pm 14 \%$). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most of Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity ($\sim10^{14}L_\odot$) of our Hot DOG sample by using IR SEDs decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction (Hickox et al. 2014). Both the high merger fraction in IR-luminous AGN sample and relatively low merger fraction in UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst dominated phase to the unobscured QSO phase.

astro-ph.GA↗

arXiv2015

Optimization and analysis of large scale data sorting algorithm based on Hadoop

When dealing with massive data sorting, we usually use Hadoop which is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. A common approach in implement of big data sorting is to use shuffle and sort phase in MapReduce based on Hadoop. However, if we use it directly, the efficiency could be very low and the load imbalance can be a big problem. In this paper we carry out an experimental study of an optimization and analysis of large scale data sorting algorithm based on hadoop. In order to reach optimization, we use more than 2 rounds MapReduce. In the first round, we use a MapReduce to take sample randomly. Then we use another MapReduce to order the data uniformly, according to the results of the first round. If the data is also too big, it will turn back to the first round and keep on. The experiments show that, it is better to use the optimized algorithm than shuffle of MapReduce to sort large scale data.

cs.DC↗