SpiderCat: A Catalog of Compact Binary Millisecond Pulsars

TL;DR

SpiderCat создаёт публичный, многофэндевый каталог компактных бинарных миллисекундных пульсаров в Галактике и связывает параметры вращения, орбиты и мультиобхватные сигнатуры от радиоприёмников до гамма-излучения. Каталог охватывает 111 систем на момент публикации, включая RB, BW и связанные классы, а также кандидатов, с детальной параметризацией и источниками данных, а также онлайн-интерфейсом и машиночитаемыми таблицами. Анализ популяционной структуры показывает слабую зависимость от высоты над плоскостью, распределение скоростей вращения и орбитальных периодов, а также различия в гравитационных и аэродинамических эффектах между RB и BW через их X- и γ-лучевые эмиссии и оптические спутники. Эти данные уточняют эволюцию MSP, расстройства ускорителей частиц в внутрилияльных шоках и характеристики уравнения состояния нейтронной звезды, а также поддерживают целенаправления поисков новых SpiderCat-источников через многоволновые наблюдения.

Abstract

We present SpiderCat, a multiwavelength catalog of all publicly known compact binary millisecond pulsars (MSPs) in the Galactic field. These systems, colloquially known as "spiders," consist of neutron stars in tight orbits with low-mass companions, which are gradually ablated by the pulsar wind. SpiderCat includes both primary subclasses$-$redbacks and black widows$-$distinguished by companion mass, as well as candidates and peculiar systems such as transitional, huntsman and tidarren MSPs. As of this initial release, SpiderCat contains 111 entries: 30 redbacks, 50 black widows, two huntsmans, 23 redback candidates, five black widow candidates, and one huntsman candidate. In this paper, we compile and summarize key parameters for each system, including spin and orbital properties, and multiwavelength data from radio, optical, X-ray, and $γ$-ray observations. An interactive, publicly accessible web interface, at https://astro.phys.ntnu.no/SpiderCAT, enables exploration and visualization of the data. The rapid growth of the number of known spiders, accelerated by the Fermi Large Area Telescope survey and its ability to identify MSPs in $γ$-rays, has opened the door to population-level studies. Utilizing SpiderCat, we analyze trends in spin period, orbital period, companion mass, emission properties, and spatial distribution. SpiderCat serves as a dynamic, multiwavelength repository for this unique class of binary pulsars, facilitating new discoveries and constraints on pulsar evolution, particle acceleration, and the neutron star equation of state.

Figures (10)

• Figure 1: Histogram showing the discovery year of spider systems included in SpiderCat, color coded by spider subclass. The discovery year is defined as the year in which a paper was published confirming the system as a spider or spider candidate, or reporting the detection of millisecond pulsations from the source. The first four spider systems are highlighted. The dramatic increase in discoveries following the launch of the Fermi $\gamma$-ray Space Telescope reflects its critical role in guiding targeted radio (e.g., 350 MHz Green Bank Telescope (GBT) and 327 MHz Arecibo surveys) and multiwavelength surveys.
• Figure 2: Number of Spiders by Type, along with the Number That Have Associated Multiwavelength Counterparts in the Catalogs Searched in This Paper and Are Also Listed in the ATNF Pulsar Catalog.
• Figure 3: Galactic distribution of spider systems in a Mollweide projection, color coded by spider subclass. The top and left panels show histograms of Galactic longitude (bin size: 12$^{\circ}$.4) and latitude (bin size: 9$^{\circ}$.5), respectively. The spider population is strongly concentrated toward low Galactic latitudes, while the distribution in Galactic longitude is relatively uniform.
• Figure 4: Histogram of estimated Galactic heights for spider systems (bin size: 0.33 kpc), color coded by spider subclass. The distribution is approximately normal, with a mean height of $\bar{z} = 0.14 \pm 0.09$ kpc and a standard deviation of $\sigma_z = 0.93 \pm 0.06$ kpc, overplotted as a scaled Gaussian (dashed line).
• Figure 5: Spin period ($P$) vs. spin period derivative ($\dot{P}$) diagram for ATNF pulsars, highlighting binaries and confirmed spider systems. Lines of constant $\dot{E}$, $B$ and $\tau$ are superposed. Also, the classical and outer magnetosphere "death lines" are shown as dashed blue and dashed-dotted green lines, respectively (see text). Histograms of $P$ and $\dot{P}$ are shown above and to the right of the plot, respectively, on a logarithmic scale for clarity. Spiders occupy the lower-left region of the $P/\dot{P}$-diagram, corresponding to the fastest-spinning, most weakly magnetized, and oldest pulsars. Two outlier systems, PSRs J2129$-$0429 and J1932$+$2121, lie above the main population, likely representing mildly recycled systems with longer spin periods and higher $\dot{P}$, indicative of alternative evolutionary paths.