The Astrophysical Journal Letters最新文献

{"title":"XMM-Newton High-resolution Spectroscopy of EXO 0748–676 after Its Reemergence from a Long Quiescence","authors":"Sayantan Bhattacharya, Sudip Bhattacharyya and Gargi Shaw","doi":"10.3847/2041-8213/ad9337","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9337","url":null,"abstract":"EXO 0748–676 is a well-studied, high-inclination, dipping and eclipsing neutron star low-mass X-ray binary that has recently emerged from 16 yr of quiescence into a new outburst. We present results from 55.5 ks of XMM-Newton observation, focusing on high-resolution spectroscopy with the same instrument (the Reflection Grating Spectrometer) that produced significant insights during the previous outburst. The XMM-Newton European Photon Imaging Camera light curve reveals a type I X-ray burst that leads to a corresponding optical burst by 3 s. To understand the effects of the burst on the ionization structure, the data are divided into burstless and pre- and postburst spectra, with additional analysis for dip and nondip phases. The primary spectral feature in all phases is a broad O vii recombination line, accompanied by velocity-broadened O viii, N vii, and Ne ix lines. Notably, the Ne ix line shows different ionization states for the preburst (11.65 Å) and postburst (13.56 Å) phases, while the dips also substantially affect the spectral lines. The current outburst mirrors many traits from the earlier one, such as a similar spectral state, plasma components with similar ionization structure, and spectral features from the same elements, implying a stable long-term accretion behavior across outbursts.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"261 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142763205","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}

{"title":"Partial Alignment of Astrometric Position Excursions of International Celestial Reference Frame Quasars with Radio Jet Structures","authors":"Valeri V. Makarov, Phil Cigan, David Gordon, Megan C. Johnson, Christopher DiLullo and Sébastien Lambert","doi":"10.3847/2041-8213/ad94f1","DOIUrl":"https://doi.org/10.3847/2041-8213/ad94f1","url":null,"abstract":"Published analyses of very long baseline interferometry data for the sources included in the third International Celestial Reference Frame catalog have revealed object-specific, excess astrometric variability and quasi-coherent trajectories as functions of time. A fraction of these sources show markedly elongated distributions of positions on the sky measured with diurnal observations. Here we apply a novel statistical and data-processing method to the diurnal position measurements stretching over 40 yr to quantify the degree of elongation and its position angle, for each source with more than 200 data points. We find that 49% of the examined sources have distribution elongations in excess of 1.3. Robust uncertainties of the directions of maximal astrometric dispersion are computed by the bootstrapping method, and the results are compared with a larger catalog of radio jet directions by A. V. Plavin et al. (2022). Nearly one-half of the sources with smaller position angle uncertainties are found to have astrometric position excursions from their mean positions aligned with the radio jet structures within ±30°.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142763256","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}

{"title":"Dominance of 2 Minute Oscillations near the Alfvén Surface","authors":"Zesen Huang, 泽森 黄, Marco Velli, Chen Shi, 辰 时, Yingjie Zhu, 英杰 朱, B. D. G. Chandran, Trevor Bowen, Victor Réville, Jia Huang, 佳 黄, Chuanpeng Hou, 传鹏 侯, Nikos Sioulas, Mingzhe Liu, 明哲 刘, Marc Pulupa, Sheng Huang, 胜 黄 and Stuart D. Bale","doi":"10.3847/2041-8213/ad9271","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9271","url":null,"abstract":"Alfvén waves, considered one of the primary candidates for heating and accelerating the fast solar wind, are ubiquitous in spacecraft observations, yet their origin remains elusive. In this study, we analyze data from the first 19 encounters of the Parker Solar Probe and report the dominance of 2 minute oscillations near the Alfvén surface. The frequency-rectified trace magnetic power spectral density (PSD) of these oscillations indicates that the fluctuation energy is concentrated around 2 minutes for the “youngest” solar wind. Further analysis using wavelet spectrograms reveals that these oscillations primarily consist of outward-propagating, spherically polarized Alfvén wave bursts. Through Doppler analysis, we show that the wave frequency observed in the spacecraft frame can be mapped directly to the launch frequency at the base of the corona, where previous studies have identified a distinct peak around 2 minutes (~8 mHz) in the spectrum of swaying motions of coronal structures observed by the Solar Dynamics Observatory Atmospheric Imaging Assembly. These findings strongly suggest that the Alfvén waves originate from the solar atmosphere. Furthermore, statistical analysis of the PSD deformation beyond the Alfvén surface supports the idea of dynamic formation of the otherwise absent 1/f range in the solar wind turbulence spectrum.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142777004","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}

{"title":"The Impact of Shear on Disk Galaxy Star Formation Rates","authors":"Xena Fortune-Bashee, Jiayi Sun, 嘉懿 孙 and Jonathan C. Tan","doi":"10.3847/2041-8213/ad91a3","DOIUrl":"https://doi.org/10.3847/2041-8213/ad91a3","url":null,"abstract":"Determining the physical processes that control galactic-scale star formation rates is essential for an improved understanding of galaxy evolution. The role of orbital shear is currently unclear, with some models expecting reduced star formation rates and efficiencies with increasing shear, e.g., if shear stabilizes gas against gravitational collapse, while others predicting enhanced rates, e.g., if shear-driven collisions between giant molecular clouds trigger star formation. Expanding on the analysis of 16 galaxies by C. Suwannajak et al., we assess the shear dependence of star formation efficiency (SFE) per orbital time (ϵorb) in 49 galaxies selected from the PHANGS-ALMA survey. In particular, we test a prediction of the shear-driven giant molecular cloud (GMC) collision model that ϵorb ∝ (1–0.7β), where , i.e., SFE per orbital time declines with decreasing shear. We fit the function ϵorb = ϵorb,0(1 − αCCβ) finding αCC ≃ 0.76 ± 0.16; an alternative fit with ϵorb normalized by the median value in each galaxy yields . These results are in good agreement with the prediction of the shear-driven GMC collision theory. We also examine the impact of a galactic bar on ϵorb finding a modest decrease in SFE in the presence of a bar, which can be attributed to lower rates of shear in these regions. We discuss the implications of our results for the GMC life cycle and environmental dependence of star formation activity.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760370","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}

{"title":"Evaluation of Several Explanations of the Strong X-Ray Polarization of the Black Hole X-Ray Binary 4U 1630-47","authors":"Henric Krawczynski, Yajie Yuan, Alexander Y. Chen, Kun Hu, Nicole Rodriguez Cavero, Sohee Chun, Ephraim Gau, James F. Steiner and Michal Dovčiak","doi":"10.3847/2041-8213/ad855c","DOIUrl":"https://doi.org/10.3847/2041-8213/ad855c","url":null,"abstract":"The Imaging X-ray Polarimetry Explorer observations of the X-ray binary 4U 1630–47 in the high soft state revealed high linear polarization degrees (PDs) rising from 6% at 2 keV to 10% at 8 keV. We discuss in this Letter three different mechanisms that impact the polarization of the observed X-rays: the reflection of gravitationally lensed emission by the accretion disk, reprocessing of the emission in outflowing plasma, and electron and ion anisotropies in the accretion disk atmosphere. We conducted detailed ray-tracing studies to evaluate the impact of the reflection of strongly gravitationally lensed emission on the PDs. Although the reflected emission can produce high PDs in the high-energy tail of the thermal emission component, we do not find models that describe the PDs and are consistent with independent estimates of the source distance. We discuss the energetics of another proposed mechanism: the emission or scattering of the X-rays in mildly relativistically moving plasma outflows. We argue that these models are disfavored as they require large mechanical luminosities on the order of, or even exceeding, the Eddington luminosity. We investigated the impact of electron and ion anisotropies but find that their impact on the observed PDs are likely negligible. We conclude with a discussion of all three effects and avenues for future research.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760662","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}

{"title":"Reliable Transmission Spectrum Extraction with a Three-parameter Limb-darkening Law","authors":"Rosa E. Keers, Alexander I. Shapiro, Nadiia M. Kostogryz, Ana Glidden, Prajwal Niraula, Benjamin V. Rackham, Sara Seager, Sami K. Solanki, Yvonne C. Unruh, Valeriy Vasilyev and Julien de Wit","doi":"10.3847/2041-8213/ad8b51","DOIUrl":"https://doi.org/10.3847/2041-8213/ad8b51","url":null,"abstract":"Stellar limb darkening must be properly accounted for to accurately determine the radii of exoplanets at various wavelengths. The standard approach to address limb darkening involves either using laws with coefficients from modeled stellar spectra or determining the coefficients empirically during light-curve fitting of the data. Here, we test how accurately three common laws—quadratic, power, and a three-parameter law—can reproduce stellar limb darkening at different wavelengths and across a broad range of stars. We show that using a quadratic limb-darkening law, which is most frequently employed by the community, leads to wavelength-dependent offsets in retrieved transmission spectra. For planets with high impact parameters (b larger than about 0.5), the amplitude of these offsets can reach 1% of the transit depth, which in some cases is comparable to and can even exceed the expected signals from the planetary atmosphere. Furthermore, the quadratic law causes an offset in the value of the impact parameter when it is determined by fitting the broadband transit light curves. In contrast, using the Kipping–Sing three-parameter law leads to robust retrievals. We advocate the use of this law in retrievals, especially for transits with large impact parameters.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760663","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}

{"title":"Three Quenched, Faint Dwarf Galaxies in the Direction of NGC 300: New Probes of Reionization and Internal Feedback","authors":"David J. Sand, Burçin Mutlu-Pakdil, Michael G. Jones, Ananthan Karunakaran, Jennifer E. Andrews, Paul Bennet, Denija Crnojević, Giuseppe Donatiello, Alex Drlica-Wagner, Catherine Fielder, David Martínez-Delgado, Clara E. Martínez-Vázquez, Kristine Spekkens, Amandine Doliva-Dolinsky, Laura C. Hunter, Jeffrey L. Carlin, William Cerny, Tehreem N. Hai, Kristen B.W. McQuinn, Andrew B. Pace and Adam Smercina","doi":"10.3847/2041-8213/ad927c","DOIUrl":"https://doi.org/10.3847/2041-8213/ad927c","url":null,"abstract":"We report the discovery of three faint and ultrafaint dwarf galaxies—Sculptor A, Sculptor B, and Sculptor C—in the direction of NGC 300 (D = 2.0 Mpc), a Large Magellanic Cloud–mass galaxy. Deep ground-based imaging with Gemini/GMOS resolves all three dwarf galaxies into stars, each displaying a red giant branch indicative of an old, metal-poor stellar population. No young stars or H i gas are apparent, and the lack of a GALEX UV detection suggests that all three systems are quenched. Sculptor C (D = 2.04 Mpc; MV = −9.1 ± 0.1 mag or LV = (3.7 ) × 105L⊙) is consistent with being a satellite of NGC 300. Sculptor A (D = 1.35 Mpc; MV = −6.9 ± 0.3 mag or LV = (5 ) × 104L⊙) is likely in the foreground of NGC 300 and at the extreme edge of the Local Group, analogous to the recently discovered ultrafaint Tucana B in terms of its physical properties and environment. Sculptor B (D = 2.48 Mpc; MV = −8.1 ± 0.3 mag or LV = (1.5 ) × 105L⊙) is likely in the background, but future distance measurements are necessary to solidify this statement. It is also of interest due to its quiescent state and low stellar mass. Both Sculptor A and B are ≳2–4 rvir from NGC 300 itself. The discovery of three dwarf galaxies in isolated or low-density environments offers an opportunity to study the varying effects of ram-pressure stripping, reionization, and internal feedback in influencing the star formation history of the faintest stellar systems.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"260 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760173","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}

{"title":"FAST H i 21 cm Study of Blueberry Galaxies","authors":"Yogesh Chandola, Chao-Wei Tsai, D. J. Saikia, Guodong Li, Di Li and Yin-Zhe Ma","doi":"10.3847/2041-8213/ad901c","DOIUrl":"https://doi.org/10.3847/2041-8213/ad901c","url":null,"abstract":"Green Peas (GPs) and blueberry galaxies (BBs) are thought to be local analogs (z < 0.1) of high redshift Lyα emitters. H i study of these can help us understand the star formation in the primordial Universe. In this Letter, we present the results of H i 21 cm study of 28 high specific star formation rate (sSFR ≳ 10−8yr −1) BBs at z ≲ 0.05 with the Five-hundred-meter Aperture Spherical radio Telescope. We report significant H i detection towards two BBs, namely J1026+0426 and J1132+0809, and discuss possible H i contribution from neighboring galaxies. The median 3σ upper limit of ∼2.0 × 108M⊙ was obtained on H i mass for galaxies with nondetections. We find BBs tend to have lower H i-to-stellar-mass ratio or gas fraction (fH i) than expected from fH i–sSFR and fH i–M* relations for main-sequence galaxies. The BBs also have a median 3σ upper limit on H i gas depletion timescale (τH i) ∼ 0.5 Gyr, about 1 order of magnitude lower than τH i for local main-sequence galaxies. We find a significantly low H i detection rate of 2/28 (7.1 %) towards these galaxies, which is similar to previous H i studies of low redshift GPs of high ionization parameter indicator, O32 ≡ O[iii]λ5007/O[ii]λ3727 ratios ≳10.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760664","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}

{"title":"A Repeating Fast Radio Burst Source in a Low-luminosity Dwarf Galaxy","authors":"Danté M. Hewitt, Mohit Bhardwaj, Alexa C. Gordon, Aida Kirichenko, Kenzie Nimmo, Shivani Bhandari, Ismaël Cognard, Wen-fai Fong, Armando Gil de Paz, Akshatha Gopinath, Jason W. T. Hessels, Franz Kirsten, Benito Marcote, Vladislavs Bezrukovs, Richard Blaauw, Justin D. Bray, Salvatore Buttaccio, Tomas Cassanelli, Pragya Chawla, Alessandro Corongiu, William Deng, Hannah N. Didehbani, Yuxin Dong, Marcin P. Gawroński, Marcello Giroletti, Lucas Guillemot, Jeff Huang, Dmitriy V. Ivanov, Ronniy C. Joseph, Victoria M. Kaspi, Mikhail A. Kharinov, Mattias Lazda, Michael Lindqvist, Giuseppe Maccaferri, Lluis Mas-Ribas, Kiyoshi W. Masui, Ryan Mckinven, Alexey Melnikov, Daniele Michilli, Andrey G. Mikhailov, Anya E. Nugent, Omar S. Ould-Boukattine, Zsolt Paragi, Aaron B. Pearlman, Ue-Li Pen, Ziggy Pleunis, Ketan R. Sand, Vishwangi Shah, Kaitlyn Shin, Mark P. Snelders, Tiziana Venturi, Na Wang, David R. A. Williams-Baldwin, Jun Yang and Jianping P. Yuan","doi":"10.3847/2041-8213/ad8ce1","DOIUrl":"https://doi.org/10.3847/2041-8213/ad8ce1","url":null,"abstract":"We present the localization and host galaxy of FRB 20190208A, a repeating source of fast radio bursts (FRBs) discovered using CHIME/FRB. As part of the Pinpointing REpeating ChIme Sources with EVN dishes repeater localization program on the European VLBI Network (EVN), we monitored FRB 20190208A for 65.6 hr at ∼1.4 GHz and detected a single burst, which led to its very long baseline interferometry localization with 260 mas uncertainty (2σ). Follow-up optical observations with the MMT Observatory (i ≳ 25.7 mag (AB)) found no visible host at the FRB position. Subsequent deeper observations with the Gran Telescopio Canarias, however, revealed an extremely faint galaxy (r = 27.32 ± 0.16 mag), very likely (99.95%) associated with FRB 20190208A. Given the dispersion measure of the FRB (∼580 pc cm−3), even the most conservative redshift estimate ( ) implies that this is the lowest-luminosity FRB host to date (≲108L⊙), even less luminous than the dwarf host of FRB 20121102A. We investigate how localization precision and the depth of optical imaging affect host association and discuss the implications of such a low-luminosity dwarf galaxy. Unlike the other repeaters with low-luminosity hosts, FRB 20190208A has a modest Faraday rotation measure of a few tens of rad m−2, and EVN plus Very Large Array observations reveal no associated compact persistent radio source. We also monitored FRB 20190208A for 40.4 hr over 2 yr as part of the Extragalactic Coherent Light from Astrophysical Transients repeating FRB monitoring campaign on the Nançay Radio Telescope and detected one burst. Our results demonstrate that, in some cases, the robust association of an FRB with a host galaxy will require both high localization precision and deep optical follow-up.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760097","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}

{"title":"Quantitative Constraint on the Contribution of Resolved Gamma-Ray Sources to the Sub-PeV Galactic Diffuse Gamma-Ray Flux Measured by the Tibet ASγ Experiment","authors":"S. Kato, M. Anzorena, D. Chen, K. Fujita, R. Garcia, J. Huang, G. Imaizumi, T. Kawashima, K. Kawata, A. Mizuno, M. Ohnishi, T. Sako, T. K. Sako, F. Sugimoto, M. Takita and Y. Yokoe","doi":"10.3847/2041-8213/ad91aa","DOIUrl":"https://doi.org/10.3847/2041-8213/ad91aa","url":null,"abstract":"Motivated by the difference between the fluxes of sub-PeV Galactic diffuse gamma-ray emission (GDE) measured by the Tibet ASγ experiment and the LHAASO collaboration, our study constrains the contribution to the GDE flux measured by Tibet ASγ from the sub-PeV gamma-ray sources in the first LHAASO catalog plus the Cygnus Cocoon. After removing the gamma-ray emission of the sources masked in the observation by Tibet ASγ, the contribution of the sources to the Tibet diffuse flux is found to be subdominant; in the sky region of 25° < l < 100° and ∣b∣ < 5°, it is less than 26.9% ± 9.9%, 34.8% ± 14.0%, and at 121 TeV, 220 TeV, and 534 TeV, respectively. In the sky region of 50° < l < 200° and ∣b∣ < 5°, the fraction is less than 24.1% ± 9.5%, 27.1% ± 11.1%, and . After subtracting the source contribution, the hadronic diffusive nature of the Tibet diffuse flux is the most natural interpretation although some contributions from very faint unresolved hadronic gamma-ray sources cannot be ruled out. Different source-masking schemes adopted by Tibet ASγ and LHAASO for their diffuse analyses result in different effective Galactic latitudinal ranges of the sky regions observed by the two experiments. Our study concludes that the effect of the different source-masking schemes leads to the observed difference between the Tibet diffuse flux measured in 25° < l < 100° and ∣b∣ < 5° and LHAASO diffuse flux in 15° < l < 125° and ∣b∣ < 5°.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753076","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}