The Astrophysical Journal Letters最新文献_第4页

Three Fast-spinning Medium-sized Hilda Asteroids Uncovered by TESS TESS发现了三颗快速旋转的中型希尔达小行星

The Astrophysical Journal Letters Pub Date : 2025-06-18 DOI: 10.3847/2041-8213/ade05b

Nóra Takács, Csaba Kiss, Róbert Szakáts, Emese Plachy, Csilla E. Kalup, Gyula M. Szabó, László Molnár, Krisztián Sárneczky, Róbert Szabó, Attila Bódi and András Pál

{"title":"Three Fast-spinning Medium-sized Hilda Asteroids Uncovered by TESS","authors":"Nóra Takács, Csaba Kiss, Róbert Szakáts, Emese Plachy, Csilla E. Kalup, Gyula M. Szabó, László Molnár, Krisztián Sárneczky, Róbert Szabó, Attila Bódi and András Pál","doi":"10.3847/2041-8213/ade05b","DOIUrl":"https://doi.org/10.3847/2041-8213/ade05b","url":null,"abstract":"Hilda asteroids, which orbit in a 3:2 resonance with Jupiter, serve as key indicators of dynamical processes in the early solar system. Their spin rates, an important probe of these mechanisms, can constrain their density and collisional evolution, offering valuable insights into their origin. In this Letter, we report on the identification of three fast-rotating Hilda asteroids with spin periods in the 3.2–3.7 hr range using data from the Transiting Exoplanet Survey Satellite. These rotation periods are significantly shorter than the previous ∼5.0 hr shortest rotation periods obtained from ground-based observations in the ∼10 km size range and are comparable with the ∼3.0 hr breakup limit of Hildas a few kilometers in size, derived from the FOSSIL survey. These fast-rotating asteroids require either considerable cohesion (in the order of a few kPa) or densities ρ ≳1.5 g cm−3, in contrast to the typically assumed ρ ≲1 g cm−3, to prevent rotational breakup. C-type asteroids, which are common in the outer main belt, have densities of ρ ≈ 1.5 g cm−3 and are known to comprise a small but notable fraction of Hildas. The observed occurrence rate of the ≤4 hr rotation periods may be explained by the 10%–15% fraction of C-type asteroids, likely mixed into these populations from the outer main belt during giant planet dynamical interactions in the early solar system.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cosmology in Extended Parameter Space with DESI Data Release 2 Baryon Acoustic Oscillations: A 2σ+ Detection of Nonzero Neutrino Masses with an Update on Dynamical Dark Energy and Lensing Anomaly 重子声学振荡：非零中微子质量的2σ+探测与动态暗能量和透镜异常的更新

The Astrophysical Journal Letters Pub Date : 2025-06-18 DOI: 10.3847/2041-8213/ade1cc

Shouvik Roy Choudhury

{"title":"Cosmology in Extended Parameter Space with DESI Data Release 2 Baryon Acoustic Oscillations: A 2σ+ Detection of Nonzero Neutrino Masses with an Update on Dynamical Dark Energy and Lensing Anomaly","authors":"Shouvik Roy Choudhury","doi":"10.3847/2041-8213/ade1cc","DOIUrl":"https://doi.org/10.3847/2041-8213/ade1cc","url":null,"abstract":"We obtain constraints in a 12 parameter cosmological model using the recent Dark Energy Spectroscopic Instrument Data Release (DR) 2 Baryon Acoustic Oscillations (BAO) data, combined with cosmic microwave background (CMB) power spectra (Planck Public Release, PR, 4) and lensing (Planck PR4 + Atacama Cosmology Telescope DR 6) data, uncalibrated Type Ia supernovae (SNe) data from Pantheon+ and Dark Energy Survey (DES) Year 5 (DESY5) samples, and Weak Lensing (WL; DES Year 1) data. The cosmological model consists of six Λ cold dark matter parameters and additionally, the dynamical dark energy parameters (w0, wa), the sum of neutrino masses (∑mν), the effective number of non-photon radiation species (Neff), the scaling of the lensing amplitude (Alens), and the running of the scalar spectral index (αs). Our major findings are the following: (i) With CMB+BAO+DESY5+WL, we obtain the first 2σ+ detection of a non-zero eV (95%). Replacing DESY5 with Pantheon+ still yields a ∼1.9σ detection. (ii) The cosmological constant lies at the edge of the 95% contour with CMB+BAO+Pantheon+ but is excluded at 2σ+ with DESY5, leaving evidence for dynamical dark energy data-set dependent and inconclusive. (iii) With CMB+BAO+SNe+WL, Alens = 1 is excluded at >2σ, while it remains consistent with unity without WL data—suggesting that the existence of lensing anomaly with Planck PR4 likelihoods may depend on non-CMB data sets. (iv) The Hubble tension persists at 3.6σ–4.2σ with CMB+BAO+SNe; WL data have minimal impact.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modification of the Power Spectral Density of Magnetic Field Fluctuations by Quasi-perpendicular Interplanetary Shocks 准垂直行星际冲击对磁场波动功率谱密度的修正

The Astrophysical Journal Letters Pub Date : 2025-06-18 DOI: 10.3847/2041-8213/ade25b

Byeongseon Park, Alexander Pitňa, Jana Šafránková and Zdeněk Němeček

{"title":"Modification of the Power Spectral Density of Magnetic Field Fluctuations by Quasi-perpendicular Interplanetary Shocks","authors":"Byeongseon Park, Alexander Pitňa, Jana Šafránková and Zdeněk Němeček","doi":"10.3847/2041-8213/ade25b","DOIUrl":"https://doi.org/10.3847/2041-8213/ade25b","url":null,"abstract":"We investigate the role of interplanetary (IP) shocks in solar wind turbulence using observations of Solar Orbiter, Parker Solar Probe, and Wind. Employing statistical analysis of quasi-perpendicular fast forward (FF) and fast reverse (FR) shocks, we revisit evolution of magnetic field turbulence across IP shocks. Our previous work indicates that the spectral properties of magnetic fluctuations are statistically conserved across different types of IP shocks, except FR shocks in the transition range of frequencies. We focus on the spectral index in the transition range ( ) using 1 minute sliding windows at 10 s intervals to probe the turbulent dissipation near shocks. We address the influence of key turbulence parameters, particularly cross helicity (σc) and fluctuation amplitude (σB), on . Our results demonstrate (1) an immediate change in across the shock with no evidence for further gradual or asymptotic evolution over extended intervals, and this implies that shock universally serves as a thin boundary separating two turbulence states; (2) the dominant factor forming the steepness of is σc, rather than σB; and (3) the statistically shallower downstream of FR shocks results from a systematic reduction in σc across shocks. These findings suggest that the observed spectral modification is primarily governed by changes in turbulence Alfvénicity, not directly by dissipation processes related to the shock, and can be commonly observed toward extensive heliospheric distances.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Heavy-metal Scenario of Ultra-high-energy Cosmic Rays 超高能量宇宙射线的重金属场景

The Astrophysical Journal Letters Pub Date : 2025-06-18 DOI: 10.3847/2041-8213/add536

Jakub Vícha, Alena Bakalová, Ana L. Müller, Olena Tkachenko and Maximilian K. Stadelmaier

引用次数: 0

Spectropolarimetry of a Nuclear Transient AT2023clx: Revealing the Geometrical Alignment between the Transient Outflow and the Nuclear Dusty Region 核瞬态AT2023clx的光谱偏振测定：揭示瞬态流出和核尘埃区之间的几何排列

The Astrophysical Journal Letters Pub Date : 2025-06-17 DOI: 10.3847/2041-8213/add71b

Kohki Uno, Keiichi Maeda, Takashi Nagao, Giorgos Leloudas, Panos Charalampopoulos, Seppo Mattila, Kentaro Aoki, Kenta Taguchi, Miho Kawabata, Javier Moldon, Miguel Pérez-Torres, Miika Pursiainen and Thomas Reynolds

{"title":"Spectropolarimetry of a Nuclear Transient AT2023clx: Revealing the Geometrical Alignment between the Transient Outflow and the Nuclear Dusty Region","authors":"Kohki Uno, Keiichi Maeda, Takashi Nagao, Giorgos Leloudas, Panos Charalampopoulos, Seppo Mattila, Kentaro Aoki, Kenta Taguchi, Miho Kawabata, Javier Moldon, Miguel Pérez-Torres, Miika Pursiainen and Thomas Reynolds","doi":"10.3847/2041-8213/add71b","DOIUrl":"https://doi.org/10.3847/2041-8213/add71b","url":null,"abstract":"AT2023clx, which occurred in NGC 3799 with a low-ionization nuclear emission-line region (LINER), is one of the most nearby nuclear transients classified as a tidal disruption event (TDE). We present three-epoch spectropolarimetric follow-up observations of AT2023clx. We detected two polarization components; one is a constant polarization of ∼1% originating from an aspherical outflow associated with the transient, while the other is a blue-excess polarization toward ∼2% originating from a nuclear dusty environment via light echoes. The polarization angle flipped by 90° between the two epochs, indicating that the outflow direction was perpendicular to the dust plane. Furthermore, the polarized flux might suggest that the nuclear dust favors relatively large grains, potentially offering constraints on its physical properties. Such polarization features—the blue excess and the 90° flip—have never been observed in previous TDE polarization samples, highlighting unique mechanisms behind AT2023clx. We propose possible scenarios: the disruption of a star formed within or captured by a nuclear dusty cloud. Given the LINER nature of NGC3799, the dusty region may possibly be linked to a torus or disk associated with a weak active galactic nucleus (AGN). Furthermore, as a more speculative scenario, the event might have been triggered by AGN-like activity, potentially linked to changing-look AGNs or ambiguous nuclear transients. These findings highlight the power of time-series spectropolarimetry of TDEs, not only in probing the origins of nuclear transients but also in investigating the physical properties of nuclear dust.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Potential-driven Metal Cycling: JADES Census of Gas-phase Metallicity for Galaxies at 1 < z < 7 电位驱动的金属循环：1 < z < 7星系气相金属丰度的JADES普查

The Astrophysical Journal Letters Pub Date : 2025-06-16 DOI: 10.3847/2041-8213/addfd9

Cheng Jia, Enci Wang, Cheqiu Lyu, Chengyu Ma, Jie Song, Yangyao Chen, Kai Wang, Haoran Yu, Zeyu Chen, Jinyang Wang, Yifan Wang and Xu Kong

{"title":"Potential-driven Metal Cycling: JADES Census of Gas-phase Metallicity for Galaxies at 1 < z < 7","authors":"Cheng Jia, Enci Wang, Cheqiu Lyu, Chengyu Ma, Jie Song, Yangyao Chen, Kai Wang, Haoran Yu, Zeyu Chen, Jinyang Wang, Yifan Wang and Xu Kong","doi":"10.3847/2041-8213/addfd9","DOIUrl":"https://doi.org/10.3847/2041-8213/addfd9","url":null,"abstract":"The gravitational potential is established as a critical determinant of gas-phase metallicity (12+log(O/H)) in low-redshift galaxies, whereas its influence remains unconfirmed at high redshifts. We investigate the correlation between gas-phase metallicity and effective radius (Re) for a sample of galaxies with redshifts ranging from 1 to 7, drawn from JWST Advanced Deep Extragalactic Survey Data Release 3. We calculate the metallicities using four strong-line methods: N2S2Hα, R23, N2, and O3N2. After taking out the evolution of size, we find that the offsets of the mass–size relation ( ) are significantly negatively correlated with the offset of the mass–metallicity relation ( ) for the four metallicity tracers. Regardless of the metallicity tracer used, we obtain Spearman rank p-values much less than 0.01, rejecting the null hypothesis that the observed correlation is statistically nonsignificant and attributable to random chance. This is also true for galaxies with z > 3, with p-values less than 0.05 for the four metallicity tracers. We for the first time find evidence of size playing a key role in determining gas-phase metallicity toward cosmic dawn, suggesting that the gravitational potential influences galaxies' material-exchange processes with the surrounding environment in the very early Universe.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"145 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NIRCam Yells at Cloud: JWST MIRI Imaging Can Directly Detect Exoplanets of the Same Temperature, Mass, Age, and Orbital Separation as Saturn and Jupiter NIRCam对云大喊大叫：JWST MIRI成像可以直接探测到与土星和木星具有相同温度、质量、年龄和轨道距离的系外行星

The Astrophysical Journal Letters Pub Date : 2025-06-16 DOI: 10.3847/2041-8213/addbde

Rachel Bowens-Rubin, James Mang, Mary Anne Limbach, Aarynn L. Carter, Kevin B. Stevenson, Kevin Wagner, Giovanni Strampelli, Caroline V. Morley, Grant Kennedy, Elisabeth Matthews, Andrew Vanderburg and Maïssa Salama

{"title":"NIRCam Yells at Cloud: JWST MIRI Imaging Can Directly Detect Exoplanets of the Same Temperature, Mass, Age, and Orbital Separation as Saturn and Jupiter","authors":"Rachel Bowens-Rubin, James Mang, Mary Anne Limbach, Aarynn L. Carter, Kevin B. Stevenson, Kevin Wagner, Giovanni Strampelli, Caroline V. Morley, Grant Kennedy, Elisabeth Matthews, Andrew Vanderburg and Maïssa Salama","doi":"10.3847/2041-8213/addbde","DOIUrl":"https://doi.org/10.3847/2041-8213/addbde","url":null,"abstract":"NIRCam and MIRI coronagraphy has successfully demonstrated the ability to directly image young sub-Jupiter-mass and mature gas giant exoplanets. However, these modes struggle to reach the sensitivities needed to find the population of cold giant planets that are similar to our own solar system’s giant planets (Teff = 60–125 K, a = 5–30 au). For the first time, we explore the high-contrast imaging capabilities of MIRI imaging rather than coronagraphy. Using data from the JWST GO 6122: Cool Kids on the Block program, which targets nearby (<6 pc) M dwarfs with NIRCam coronagraphy and MIRI imaging, we demonstrate that 21 μm MIRI imaging can detect planets with the same temperature, mass, age, and orbital separations as Saturn and Jupiter. For systems within 3 pc, 21 μm MIRI imaging reaches the sensitivity needed to detect planets colder than Saturn (<95 K). NIRCam coronagraphy can achieve similar results only in the unlikely case that a cold giant planet is cloud-free. Motivated by these compelling findings, we extend our analysis to evaluate the measured performance of MIRI F2100W imaging versus NIRCam F444W coronagraphy to 70 pc and conclude that MIRI imaging offers the advantage for systems within 20 pc. Microlensing surveys predict an occurrence rate as high as one to two low-mass giant exoplanets per star, suggesting that JWST MIRI imaging surveys of nearby systems may be poised to uncover a substantial population. This breakthrough enables a path toward the first direct characterization of cold giant exoplanets that are analogous to the solar system giant planets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intermittency in Interplanetary Coronal Mass Ejections Observed by Parker Solar Probe and Solar Orbiter 帕克太阳探测器和太阳轨道器观测到的行星际日冕物质抛射的间歇性

The Astrophysical Journal Letters Pub Date : 2025-06-16 DOI: 10.3847/2041-8213/ade0b0

Julia Ruohotie, Simon Good, Christian Möstl and Emilia Kilpua

{"title":"Intermittency in Interplanetary Coronal Mass Ejections Observed by Parker Solar Probe and Solar Orbiter","authors":"Julia Ruohotie, Simon Good, Christian Möstl and Emilia Kilpua","doi":"10.3847/2041-8213/ade0b0","DOIUrl":"https://doi.org/10.3847/2041-8213/ade0b0","url":null,"abstract":"Intermittency has been studied extensively in the fast and slow solar winds but to a far lesser extent in interplanetary coronal mass ejections (ICMEs). While ICMEs are often characterized by their relatively smooth, large-scale magnetic flux rope structures, a spectrum of fluctuations is nonetheless present at smaller scales. We have examined kurtosis and its scaling exponents at magnetohydrodynamic inertial scales in 49 ICMEs observed between 0.25 and 1 au by Parker Solar Probe and Solar Orbiter, and compared the results to those obtained for the ICME sheath regions and ambient solar wind intervals. Kurtosis behaves similarly in all intervals studied and presents a universal behavior typical of intermittent time series. The ICMEs displayed a radially invariant level of intermittency, suggesting that they are relatively static, well-developed turbulent environments. In the sheath regions, the level of intermittency increased with distance, indicating that the turbulence is not yet fully developed at small heliocentric distances. In addition to intermittent fluctuations related to turbulence, the sheath regions may possess a population of nonturbulent structures that increase the absolute value of kurtosis.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"196 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Tale of Dynamical Instabilities and Giant Impacts in the Exoplanet Radius Valley 关于系外行星半径谷的动力不稳定性和巨大影响的故事

The Astrophysical Journal Letters Pub Date : 2025-06-16 DOI: 10.3847/2041-8213/adde51

Sho Shibata and Andre Izidoro

{"title":"A Tale of Dynamical Instabilities and Giant Impacts in the Exoplanet Radius Valley","authors":"Sho Shibata and Andre Izidoro","doi":"10.3847/2041-8213/adde51","DOIUrl":"https://doi.org/10.3847/2041-8213/adde51","url":null,"abstract":"The size distribution of planets with radii between 1R⊕ and 4R⊕ peaks near 1.4R⊕ and 2.2R⊕, with a dip around 1.8R⊕—the so-called “radius valley.” Recent statistical analyses suggest that planets within this valley (1.5 < R < 2R⊕) tend to have slightly higher orbital eccentricities than those outside it. The origin of this dynamical signature remains unclear. We revisit the “breaking the chains” formation model and propose that late dynamical instabilities—occurring after disk dispersal—may account for the elevated eccentricities observed in the radius valley. Our simulations show that subvalley planets (R < 2R⊕) are generally rocky, while those beyond the valley (R > 2R⊕) are typically water-rich. Rocky planets that undergo strong dynamical instabilities and numerous late giant impacts have their orbits excited and their radii increased, ultimately placing them into the radius valley. In contrast, the larger, water-rich planets just beyond the valley experience weaker instabilities and fewer impacts, resulting in lower eccentricities. This contrast leads to a peak in the eccentricity distribution within the valley. The extent to which planets in the radius valley are dynamically excited depends sensitively on the orbital architecture before the orbital instability. Elevated eccentricities among radius valley planets arise primarily in scenarios that form a sufficiently large number of rocky planets within 100 days (typically ≳5) prior to instability, and that also host external perturbers (P > 100 days), which further amplify the strength of dynamical instabilities.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Candidate Dark Galaxy-2: Validation and Analysis of an Almost Dark Galaxy in the Perseus Cluster 候选暗星系-2：英仙座星系团中近乎暗星系的验证与分析

The Astrophysical Journal Letters Pub Date : 2025-06-15 DOI: 10.3847/2041-8213/adddab

Dayi (David) Li, 大一李, Qing Liu, 青刘, Gwendolyn M. Eadie, Roberto G. Abraham, Francine R. Marleau, William E. Harris, Pieter van Dokkum, Aaron J. Romanowsky, Shany Danieli, Patrick E. Brown and Alex Stringer

{"title":"Candidate Dark Galaxy-2: Validation and Analysis of an Almost Dark Galaxy in the Perseus Cluster","authors":"Dayi (David) Li, 大一李, Qing Liu, 青刘, Gwendolyn M. Eadie, Roberto G. Abraham, Francine R. Marleau, William E. Harris, Pieter van Dokkum, Aaron J. Romanowsky, Shany Danieli, Patrick E. Brown and Alex Stringer","doi":"10.3847/2041-8213/adddab","DOIUrl":"https://doi.org/10.3847/2041-8213/adddab","url":null,"abstract":"Candidate Dark Galaxy-2 (CDG-2) is a potential dark galaxy consisting of four globular clusters (GCs) in the Perseus cluster, first identified in D. Li et al. through a sophisticated statistical method. The method searched for overdensities of GCs from a Hubble Space Telescope (HST) survey targeting Perseus. Using the same HST images and new imaging data from the Euclid survey, we report the detection of extremely faint but significant diffuse emission around the four GCs of CDG-2. We thus have exceptionally strong evidence that CDG-2 is a galaxy. This is the first galaxy detected purely through its GC population. Under the conservative assumption that the four GCs make up the entire GC population, preliminary analysis shows that CDG-2 has a total luminosity of LV,gal = 6.2 ± 3.0 × 106 L⊙ and a minimum GC luminosity of LV,GC = 1.03 ± 0.2 × 106 L⊙. Our results indicate that CDG-2 is one of the faintest galaxies having associated GCs, while at least ∼16.6% of its light is contained in its GC population. This ratio is likely to be much higher (∼33%) if CDG-2 has a canonical GC luminosity function (GCLF). In addition, if the previously observed GC-to-halo mass relations apply to CDG-2, it would have a minimum dark matter halo mass fraction of 99.94% to 99.98%. If it has a canonical GCLF, then the dark matter halo mass fraction is ≳99.99%. Therefore, CDG-2 may be the most GC dominated galaxy and potentially one of the most dark matter dominated galaxies ever discovered.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"230 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0