Astronomische Nachrichten最新文献_第2页

Solar disk integration polarimeter: An automated disk-integration full-Stokes-vector solar feed for the Potsdam Echelle Polarimetric and Spectroscopic Instrument spectrograph 日盘积分偏振仪：波茨坦埃歇尔偏振和分光仪器光谱仪的自动日盘积分全斯托克斯矢量太阳馈源

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-07-16 DOI: 10.1002/asna.20240033

Klaus G. Strassmeier, Ilya Ilyin, Manfred Woche, Frank Dionies, Michael Weber, Arto Järvinen, Carsten Denker, Ekaterina Dineva, Meetu Verma, Thomas Granzer, Wilbert Bittner, Svend-Marian Bauer, Jens Paschke, Hakan Önel

{"title":"Solar disk integration polarimeter: An automated disk-integration full-Stokes-vector solar feed for the Potsdam Echelle Polarimetric and Spectroscopic Instrument spectrograph","authors":"Klaus G. Strassmeier, Ilya Ilyin, Manfred Woche, Frank Dionies, Michael Weber, Arto Järvinen, Carsten Denker, Ekaterina Dineva, Meetu Verma, Thomas Granzer, Wilbert Bittner, Svend-Marian Bauer, Jens Paschke, Hakan Önel","doi":"10.1002/asna.20240033","DOIUrl":"10.1002/asna.20240033","url":null,"abstract":"We introduce a new solar feed for the PEPSI nighttime spectrograph of the LBT. It enables spectroscopy of the Sun-as-a-star in circular polarization (CP) and linear polarization (LP) with a spectral resolution of 250,000 (≈0.025Å or <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>600</mn>\u0000 <mspace></mspace>\u0000 <mi>m</mi>\u0000 <mspace></mspace>\u0000 <msup>\u0000 <mi>s</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ 600kern0.1em mathrm{m}kern0.1em {mathrm{s}}^{-1} $$</annotation>\u0000 </semantics></math>) for the wavelength range 383–907 nm. The polarimeter is a dual-beam design with a modified Wollaston prism as beam splitter and linear polarizer combined with a retractable super-achromatic <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>λ</mi>\u0000 <mo>/</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 <annotation>$$ lambda /4 $$</annotation>\u0000 </semantics></math> retarder. The Wollaston beam diameter is 14 mm and large enough that it does not require a classical telescopic feed anymore. Both polarimetric beams are re-imaged into respective integration spheres from which two fibers feed the scrambled light to the spectrograph. The system is fully automated in the sense that it finds the Sun in the morning, closes the guider loop, observes a predefined number of individual spectra, and moves to a home position at the end of the day. Among the scientific aims is Zeeman–Doppler imaging of the Sun as a star over the next activity cycle. Our first-light application detects a clear Stokes-V/I profile with a full amplitude of <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ 1times {10}^{-4} $$</annotation>\u0000 </semantics></math> on, for example, October 13, 2023, suggesting a solar disk-averaged line-of-sight net magnetic field of +0.37±0.02 G. Comparison of this value with a contemporary full-disk line-of-sight magnetogram suggests an unsigned mean field of about ≈13 G.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluating a sigmoid dark energy model to explain the Hubble tension 评估解释哈勃张力的西格玛暗能量模型

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-07-15 DOI: 10.1002/asna.20240034

Sergio Torres-Arzayus, Camilo Delgado-Correal, Mario-Armando Higuera-G, Sebastián Rueda-Blanco

{"title":"Evaluating a sigmoid dark energy model to explain the Hubble tension","authors":"Sergio Torres-Arzayus, Camilo Delgado-Correal, Mario-Armando Higuera-G, Sebastián Rueda-Blanco","doi":"10.1002/asna.20240034","DOIUrl":"10.1002/asna.20240034","url":null,"abstract":"In this study, we analyze Type Ia supernovae (SNe Ia) data sourced from the Pantheon+ compilation to investigate late-time physics effects influencing the expansion history, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>H</mi>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>z</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$$ H(z) $$</annotation>\u0000 </semantics></math>, at redshifts <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>z</mi>\u0000 <mo><</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$$ left(z<2right) $$</annotation>\u0000 </semantics></math>. Our focus centers on a time-varying dark energy (DE) model that introduces a rapid transition in the equation of state, at a specific redshift, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>z</mi>\u0000 <mi>a</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {z}_a $$</annotation>\u0000 </semantics></math>, from the baseline, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>w</mi>\u0000 <mi>Λ</mi>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <annotation>$$ {w}_{Lambda}=-1 $$</annotation>\u0000 </semantics></math>, value to the present value, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>w</mi>\u0000 <mn>0</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {w}_0 $$</annotation>\u0000 </semantics></math>. The change in the equation of state is implemented as a transition in the DE density scale factor driven by a sigmoid function. The constraints obtained for the DE sigmoid phenomenological parametrization have broad applicability for dynamic DE models that invoke late-time physics. Our analysis indicates that the sigmoid model provides a slightly better, though not statistically significant, fit to the SNe Pantheon+ data compared to the standard <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Λ</mi>\u0000 </mrow>\u0000 <annotation>$$ Lambda $$</annotation>\u0000 </semantics></math> cold dark matter (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ΛCDM</mi>\u0000 </mrow>\u0000 <annotation>$$ Lambda mathrm{CDM}","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Size of the accretion disc in the recurrent nova T CrB 周期新星 T CrB 的吸积盘大小

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-07-15 DOI: 10.1002/asna.20240036

R. K. Zamanov, K. A. Stoyanov, V. Marchev, M. Minev, D. Marchev, M. Moyseev, J. Martí, M. F. Bode, R. Konstantinova-Antova, S. Stefanov

{"title":"Size of the accretion disc in the recurrent nova T CrB","authors":"R. K. Zamanov, K. A. Stoyanov, V. Marchev, M. Minev, D. Marchev, M. Moyseev, J. Martí, M. F. Bode, R. Konstantinova-Antova, S. Stefanov","doi":"10.1002/asna.20240036","DOIUrl":"10.1002/asna.20240036","url":null,"abstract":"We present high-resolution (0.06 Å px<math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mo> </mo>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {}^{-1} $$</annotation>\u0000 </semantics></math>) spectroscopic observations of the recurrent nova T Coronae Borealis obtained during the last 1.5 years (September 2022–January 2024), with the 2.0-m RCC telescope of the Rozhen National Astronomical Observatory, Bulgaria. Double-peaked emission is visible in the <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mi>α</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {H}_{alpha } $$</annotation>\u0000 </semantics></math> line after the end of the superactive state. We subtract the red giant contribution and measure the distance between the peaks (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <msub>\u0000 <mi>v</mi>\u0000 <mi>a</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ Delta {v}_a $$</annotation>\u0000 </semantics></math>) of the line. For the period July 2023–January 2024, we find that <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <msub>\u0000 <mi>v</mi>\u0000 <mi>a</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ Delta {v}_a $$</annotation>\u0000 </semantics></math> is in range <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>90</mn>\u0000 <mo><</mo>\u0000 <mi>Δ</mi>\u0000 <msub>\u0000 <mi>v</mi>\u0000 <mi>a</mi>\u0000 </msub>\u0000 <mo><</mo>\u0000 <mn>120</mn>\u0000 </mrow>\u0000 <annotation>$$ 90<Delta {v}_a<120 $$</annotation>\u0000 </semantics></math> km s<math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mo> </mo>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {}^{-1} $$</annotation>\u0000 </semantics></math>. Assuming that the emission is from the accretion disc around the white dwarf, we find average radius of the accretion disc <math>\u0000 <semantics>\u0000 <mrow>\u0000 ","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spectroscopic and dynamic orbital analyses of metal-poor and high proper-motion stars: I. HD 8724 and HD 195633 贫金属和高正确运动恒星的光谱和动态轨道分析：I. HD 8724 和 HD 195633

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-07-12 DOI: 10.1002/asna.20240047

M. Marışmak, T. Şahin, F. Güney, O. Plevne, S. Bilir

{"title":"Spectroscopic and dynamic orbital analyses of metal-poor and high proper-motion stars: I. HD 8724 and HD 195633","authors":"M. Marışmak, T. Şahin, F. Güney, O. Plevne, S. Bilir","doi":"10.1002/asna.20240047","DOIUrl":"10.1002/asna.20240047","url":null,"abstract":"In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal-poor and high proper-motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters: Teff = 4700 ± 115 K, log g = 1.65 ± 0.32 cgs, [Fe/H] = −1.59 ± 0.04 dex, and a microturbulent velocity <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ξ</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation>$$ xi = $$</annotation>\u0000 </semantics></math> 1.58 ± 0.50 km s−1 for HD 8724 and Teff = 6100 ± 205 K, log g = 3.95 ± 0.35 cgs, [Fe/H] = −0.52 ± 0.05 dex, and <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ξ</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation>$$ xi = $$</annotation>\u0000 </semantics></math>1.26 ± 0.50 km s−1 for HD 195633. The ages were estimated using a Bayesian approach (12.25 Gyr for HD 8724 and 8.15 Gyr for HD 195633). The escape scenarios of these stars from 170 candidate globular clusters (GCs) in the Galaxy were also investigated because of their chemical and physical differences (HPM and metal-poor nature). Accordingly, the calculated probability of encounter (59%) for HD 8724 at a distance of five tidal radius suggests that star HD 8724 may have escaped from NGC 5139 (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ω</mi>\u0000 </mrow>\u0000 <annotation>$$ omega $$</annotation>\u0000 </semantics></math> Cen), supported by its highly flattened orbit and may belong to a subpopulation of this GC. Conversely, HD 195633's kinematics, age, and metal abundances point toward an escape from the bulge GC NGC 6356.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Mira discovery problem—Observations by David Fabricius in 1596 and 1609 (and by others before?): Positional accuracy, brightness, color index, and period 米拉发现问题--大卫-法布里西乌斯（David Fabricius）在 1596 年和 1609 年的观测（以及之前其他人的观测？定位精度、亮度、色彩指数和周期

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-07-02 DOI: 10.1002/asna.20230131

R. Neuhäuser, D. L. Neuhäuser, M. Mugrauer, D. Luge, J. Chapman

{"title":"The Mira discovery problem—Observations by David Fabricius in 1596 and 1609 (and by others before?): Positional accuracy, brightness, color index, and period","authors":"R. Neuhäuser, D. L. Neuhäuser, M. Mugrauer, D. Luge, J. Chapman","doi":"10.1002/asna.20230131","DOIUrl":"10.1002/asna.20230131","url":null,"abstract":"The pulsating variable star Mira (o Ceti) was observed by David Fabricius (Frisia) in 1596 and 1609. We review suggested previous detections (e.g., China, Hipparchos). We analyze all Mira records from Fabricius in their historical context. Fabricius measured the separation of Mira to other stars to ±1.6−1.7′. From his texts, we derive a brightness (slightly brighter than Hamal) of ca. 1.9±0.1 mag and a color index B-V<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≃</mo>\u0000 </mrow>\u0000 <annotation>$$ simeq $$</annotation>\u0000 </semantics></math>1.3−1.4 mag (‘like Mars’) for 1596 Aug 3 (Jul.). Mira started to fainten 19 days later and was observed until mid/late Oct. We show why such a red star cannot be followed by the naked eye until ca. 6 mag: For Mira's color at disappearance and altitude from Frisia, the limit is reduced by ca. 1.0 mag. Since Fabricius connected the Mira brightening with the close-by prograde Jupiter, he re-detected it only 12 years later, probably shortly before a relatively bright maximum—discoveries are strongly affected by biases. A Mira period of 330.2 days is consistent with both the oldest data (from Fabricius 1596 to Hevelius 1660) and the most current data (VSX 2004–2023), so that we see no evidence for secular period or phase shifts. (We also present Fabricius' observations of P Cygni in 1602.)","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Updated absolute parameters and kinematics of IS CMa 更新的IS CMa绝对参数和运动学参数

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-06-23 DOI: 10.1002/asna.20240038

Serkan Evcil, Simge Adalalı, Neslihan Alan, Remziye Canbay, Selcuk Bilir

{"title":"Updated absolute parameters and kinematics of IS CMa","authors":"Serkan Evcil, Simge Adalalı, Neslihan Alan, Remziye Canbay, Selcuk Bilir","doi":"10.1002/asna.20240038","DOIUrl":"10.1002/asna.20240038","url":null,"abstract":"Eclipsing binary systems are significant objects for astrophysics in that direct observations can determine the fundamental parameters of stars. In this study, we precisely determined the fundamental parameters of the binary component stars obtained by simultaneous analysis of radial velocities and the TESS light curve using the Wilson and Devinney code. Following the analysis, the masses and radii of the primary and secondary components were determined as <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>1.58</mn>\u0000 <mo>±</mo>\u0000 <mn>0.01</mn>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {M}_1=1.58pm 0.01{M}_{odot } $$</annotation>\u0000 </semantics></math>, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>0.48</mn>\u0000 <mo>±</mo>\u0000 <mn>0.02</mn>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {M}_2=0.48pm 0.02{M}_{odot } $$</annotation>\u0000 </semantics></math>, and <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>1.93</mn>\u0000 <mo>±</mo>\u0000 <mn>0.01</mn>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {R}_1=1.93pm 0.01{R}_{odot } $$</annotation>\u0000 </semantics></math>, <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>1.14</mn>\u0000 <mo>±</mo>\u0000 <mn>0.01</mn>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {R}_2=1.14pm 0.01{R}_{odot } $$</annotation>\u0000 </semantics></math>, respectively. Furthermore, the distance of IS CMa is calculated as <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>92.7</mn>\u0000 <mo>±</mo>\u0000 <mn>6.5</mn>\u0000 </mrow>\u0000 <annotation>$$ 92.7pm 6.5 $$</annotation>\u0000 </semantics></math>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unraveling the link between Type II supernova luminosity and host galaxy velocity dispersion 揭示II型超新星光度与宿主星系速度色散之间的联系

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-06-18 DOI: 10.1002/asna.20230146

A. Hernández Flores, F. Olivares E., L. Morelli, P. Wiseman, C. P. Gutierrez

{"title":"Unraveling the link between Type II supernova luminosity and host galaxy velocity dispersion","authors":"A. Hernández Flores, F. Olivares E., L. Morelli, P. Wiseman, C. P. Gutierrez","doi":"10.1002/asna.20230146","DOIUrl":"https://doi.org/10.1002/asna.20230146","url":null,"abstract":"Type II supernovae (SNe II) have emerged as valuable cosmological probes, serving as alternative and independent tools to Type Ia supernova (SN Ia) cosmology. However, the Hubble diagram dispersion for SNe II is significantly larger than for SNe Ia. In this study, we investigate the SN II luminosity and the host galaxy velocity dispersion with the purpose of improving the scatter in the SN II Hubble diagram. We selected a sample of SNe II discovered by the Dark Energy Survey (DES), and we measured the spectra of their host galaxies using the VLT/FORS2 and Magellan-Baade/MagE spectrographs. From those galaxy spectra, we calculated the stellar velocity dispersion in the central region. Using the effective Sérsic radius from the DES imaging, we standardized the velocity dispersion values to a common aperture. From their i-band light curves, we determined a characteristic plateau brightness for our SNe. For this purpose, we developed an algorithm designed to parameterize the plateau phase. After computing the SN absolute magnitudes using the standard cosmology, we found a modest correlation with the host galaxy velocity dispersion (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <mo>=</mo>\u0000 <mn>0.57</mn>\u0000 </mrow>\u0000 <annotation>$$ {R}^2=0.57 $$</annotation>\u0000 </semantics></math>). These findings could significantly contribute to SN II cosmology, paving the way for SNe II as more robust cosmological probes.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Picture: Astron. Nachr. 6/2024 封面图片：Astron.Nachr.6/2024

IF 0.9 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-06-17 DOI: 10.1002/asna.20249014

Michele Scalco, Roman Gerasimov, Luigi R. Bedin, Enrico Vesperini, Domenico Nardiello, Maurizio Salaris, Adam Burgasser, Jay Anderson, Mattia Libralato, Andrea Bellini, Piero Rosati

{"title":"Cover Picture: Astron. Nachr. 6/2024","authors":"Michele Scalco, Roman Gerasimov, Luigi R. Bedin, Enrico Vesperini, Domenico Nardiello, Maurizio Salaris, Adam Burgasser, Jay Anderson, Mattia Libralato, Andrea Bellini, Piero Rosati","doi":"10.1002/asna.20249014","DOIUrl":"https://doi.org/10.1002/asna.20249014","url":null,"abstract":"Color-magnitude diagram of the lower mass end of the Main Sequence of globular cluster NGC 6752, as derived from NIR images of a deep field observed under a HST Large Programme led by L.R.Bedin. Three main stellar populations can be reliably distinguished within this cluster. The three isochrones (blue, green, and red lines) were computed with different chemical compositions, adjusted to match the observed colors of the different generations of stars at an age of 12.63 Gy. In the lower left part of the plot, the corresponding isochrone for the White Dwarfs (at an age of 12.5 Gy) is shown in purple, together with the three WD candidates shown as orange crosses. For each isochrone, specific mass values are marked by labeled filled dots. A detailed analysis of the HST data and a discussion of possible scenarios for the formation of multiple stellar populations within NGC 6752 is presented in the article by Scalco et al., this issue e240018.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture>\u0000 </div>\u0000 </figure>\u0000 ","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20249014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Issue Information: Astron. Nachr. 06/2024 发行信息：Astron.Nachr.06/2024

IF 0.9 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-06-17 DOI: 10.1002/asna.20249005

引用次数: 0

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397 JWST 对最接近球状星团的成像-I.NGC 6397 中白矮星可能存在的红外线过量

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-05-27 DOI: 10.1002/asna.20240039

L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini

{"title":"JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397","authors":"L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini","doi":"10.1002/asna.20240039","DOIUrl":"10.1002/asna.20240039","url":null,"abstract":"We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against) the existence of ancient planetary systems. The existing archival Hubble Space Telescope imaging data obtained <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mn>18</mn>\u0000 </mrow>\u0000 <annotation>$$ sim 18 $$</annotation>\u0000 </semantics></math> years ago reach ultra-deep optical magnitudes (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>V</mi>\u0000 <mo>∼</mo>\u0000 <mn>31</mn>\u0000 </mrow>\u0000 <annotation>$$ Vsim 31 $$</annotation>\u0000 </semantics></math>) and allow us to derive a near-perfect separation between field and cluster members. We detect an apparent split in the lower part of the WD CS of NGC 6397. The red part of the WD CS, containing about 25% of the total, exhibits significant IR-excess of up to <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <msub>\u0000 <mi>m</mi>\u0000 <mrow>\u0000 <mi>F</mi>\u0000 <mn>322</mn>\u0000 <mi>W</mi>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msub>\u0000 <mo>∼</mo>\u0000 <mn>0.5</mn>\u0000 </mrow>\u0000 <annotation>$$ Delta {m}_{mathrm{F}322mathrm{W}2}sim 0.5 $$</annotation>\u0000 </semantics></math> mag. These infrared excesses require both theoretical and observational follow-ups to confirm their veracity and to ascertain their true nature.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141192057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0