Astronomical data analysis software and systems

Solar, Mauricio; Bayo, A.; Lorente, Nuria P. F.; Pichara, Karim

doi:10.1016/j.ascom.2018.10.009

Cited by 11 publications

(11 citation statements)

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“…This investigation is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. (Arnaud 1996), numpy (Harris et al 2020), scipy (Virtanen et al 2020)…”

Section: Discussionmentioning

confidence: 99%

Do Central Compact Objects have Carbon Atmospheres?

Alford¹,

Gotthelf²,

Halpern³

2023

ApJ

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Only three of the dozen central compact objects (CCOs) in supernova remnants (SNRs) show thermal X-ray pulsations due to nonuniform surface temperature (hot spots). The absence of X-ray pulsations from several unpulsed CCOs has motivated suggestions that they have uniform-temperature carbon atmospheres (UTCAs), which adequately fit their spectra with appropriate neutron star (NS) surface areas. This is in contrast to the two-temperature blackbody or hydrogen atmospheres that also fit well. Here we investigate the applicability of UTCAs to CCOs. We show the following: (i) The phase-averaged spectra of the three pulsed CCOs can also be fitted with a UTCA of the appropriate NS area, despite pulsed CCOs manifestly having nonuniform surface temperature. A good spectral fit is therefore not strong support for the UTCA model of unpulsed CCOs. (ii) An improved spectrum of one unpulsed CCO, previously analyzed with a UTCA, does not allow an acceptable fit. (iii) For two unpulsed CCOs, the UTCA does not allow a distance compatible with the SNR distance. These results imply that, in general, CCOs must have hot, localized regions on the NS surface. We derive new X-ray pulse modulation upper limits on the unpulsed CCOs, and constrain their hot spot sizes and locations. We develop an alternative model that accounts for both the pulsed and unpulsed CCOs: a range of angles between hot spot and rotation axes consistent with an exponential distribution with scale factor λ ∼ 20°. We discuss the physical mechanisms that could produce such small angles and small hot spots.

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Section: Discussionmentioning

confidence: 99%

Do Central Compact Objects have Carbon Atmospheres?

Alford¹,

Gotthelf²,

Halpern³

2023

ApJ

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“…M. M. is financially supported by the Hakubi project of Kyoto University. Facilities: NICER Software: XSPEC 12.12.1 (Arnaud 1996), HEAsoft 6.30 (Blackburn 1995; Nasa High Energy Astrophysics Science Archive Research Center (Heasarc) 2014), astropy 5.1 (Robitaille et al 2013;The Astropy Collaboration 2018, 2022), matplotlib 3.5.2 (Hunter 2007) numpy 1.22.3 (Harris et al 2020, scipy 1.7.1 (Virtanen et al 2020) tensorflow 0.14.0 (Abadi et al 2016)…”

Section: Discussionmentioning

confidence: 99%

X-ray time lag evaluation of MAXI J1820+070 with a differential cross-correlation analysis

Omama¹,

Tsujimoto²,

Ebisawa³

et al. 2023

Preprint

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MAXI J1820+070 is a transient black hole binary (BHB) discovered on 2018 March 11. The unprecedented rich statistics brought by the NICER X-ray telescope allows detailed timing analysis up to ∼1 kHz uncompromised by the photon shot noise. To estimate the time lags, the Fourier analysis was applied, which led to two different conclusions for the system configuration; one supporting the lamp-post configuration with a stable accretion disk extending close to the innermost stable circular orbit and the other supporting the truncated accretion disk contracting with time. Using the same data set, we present the results based on the cross-correlation function (CCF). The CCF is calculated between two different X-ray bands and one side is subtracted from the other side, which we call the differential CCF (dCCF). The soft and hard lags respectively of ∼0.03 and 3 s are clearly identified without being diluted by the spectral mixture, demonstrating the effectiveness of the dCCF analysis. The evolution of these lags is tracked, along with spectral changes for the first 120 days since the discovery. Both the dCCF and spectral fitting results are interpreted that the soft lag is a reverberation lag between the Comptonized emission and the soft excess emission and that the hard lag is between the disk black body emission and the Comptonized emission. The evolution of these lags is in line with the picture of the truncated disk contracting with time.

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“…Our shallow HST data already reveal hints of complex star forming filaments, which will benefit from deeper observations with HST or perhaps even JWST/NIRSpec IFU in order to more precisely measure SFRs and reddening, and further understand the under-lying process of cluster star formation in a previously untapped redshift regime. 2013), numpy (Harris et al 2020), scipy (Virtanen et al 2020), pandas (Reback et al 2022), CIAO (Fruscione et al 2006), XSPEC (Arnaud 1996). Prospector (Johnson et al 2021), python-FSPS (Foreman-Mackey et al 2014, SEDpy (Johnson 2021), matplotlib (Hunter 2020), seaborn (Waskom 2021), jupyter/IPython Notebooks (Kluyver et al 2016), SAOImage DS9 (Joye & Mandel 2003), pyRAF (Science Software Branch at STScI 2012), Source Extractor (Bertin & Arnouts 1996)…”

Section: Discussionmentioning

confidence: 99%

SPT-CL J2215-3537: A Massive Starburst at the Center of the Most Distant Relaxed Galaxy Cluster

Calzadilla¹,

Bleem²,

McDonald³

et al. 2023

Preprint

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We present the discovery of the most distant, dynamically relaxed cool core cluster, SPT-CL J2215-3537 (SPT2215) and its central brightest cluster galaxy (BCG) at z = 1.16. Using new X-ray observations, we demonstrate that SPT2215 harbors a strong cool core, with a central cooling time of 200 Myr (at 10 kpc) and a maximal intracluster medium cooling rate of 1900 ± 400 M yr −1 . This prodigious cooling may be responsible for fueling extended, star-forming filaments observed in Hubble Space Telescope imaging. Based on new spectrophotometric data, we detect bright [O ii] emission in the BCG, implying an unobscured star formation rate (SFR) of 320 +230 −140 M yr −1 . The detection of a weak radio source (2.0±0.8 mJy at 0.8 GHz) suggests ongoing feedback from an active galactic nucleus (AGN), though the implied jet power is less than half the cooling luminosity of the hot gas, consistent with cooling overpowering heating. The extreme cooling and SFR of SPT2215 is rare among known cool core clusters, and it is even more remarkable that we observe these at such high redshift, when most clusters are still dynamically disturbed. The high mass of this cluster, coupled with the fact that it is dynamically relaxed with a highly-isolated BCG, suggests that it is an exceptionally rare system that must have formed very rapidly in the early Universe. Combined with the high SFR, SPT2215 may be a high-z analog of the Phoenix cluster, potentially providing insight into the limits of AGN feedback and star formation in the most massive galaxies.

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Astronomical data analysis software and systems

Cited by 11 publications

References 0 publications

Do Central Compact Objects have Carbon Atmospheres?

Do Central Compact Objects have Carbon Atmospheres?

X-ray time lag evaluation of MAXI J1820+070 with a differential cross-correlation analysis

SPT-CL J2215-3537: A Massive Starburst at the Center of the Most Distant Relaxed Galaxy Cluster

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