arXiv subjects

Monika Adamów

Publications and source records attributed to Monika Adamów.

9 recordsLinked to original sources

arXiv2026

Joint Observations of PTPS Targets (JOTA). Combined spectroscopic and photometric analysis of 16 SB1 systems

Context. The Pennsylvania-Toru\'n Planet Search, which operates on a sample of $\sim$1000 northern-hemisphere stars, has been underway since 2004. Stars with radial velocity (RV) amplitudes exceeding 2 km s$^{-1}$ represent a backup subprogram sample dedicated to monitoring binary stars with multiple instruments. Aims. We used almost 21 years of combined RV measurements to search for Doppler signals consistent with stellar or brown dwarf companions and to produce a catalog of both known and previously unpublished binary stars in our planet-search sample. Methods. We analyzed the combined RV measurements, searching for stellar companions and obtaining orbital solutions for both known and new binary systems. We also searched for periods in available long-term photometric monitoring data from All Sky Automated Survey (ASAS), and applied Gaia astrometric data whenever available. Results. We report the results of long-term RV monitoring of 16 systems: new detections of low-mass companions to 11 stars and updated orbital elements based on combined sets of our new and literature data for five systems. For two objects (TYC 3318-00789-1 and TYC 3318-01538-1), we find evidence of activity or the influence of another unseen companion, possibly due to line-profile variations or unresolved spectral contamination. We present true masses for three systems in our sample: TYC 1931-1040-1, TYC 3451- 1449-1, and TYC 3667-1636-1. We obtained these masses using Gaia DR3 non-single star data.

astro-ph.SR↗

arXiv2025

Planetary-mass companions to a retired B star BD+37 3172 and a retired F star BD+42 2315

Radial velocity searches may lead to detection of exoplanets at large orbital separations only if long-enough time-series of data are available. Therefore publication of precise measurements collected in the past is very valuable even if not successfully completed with a definitive detection. Here we present 309 precise ($\sigma$RV$\approx$5-7 m s$^{-1}$) multi-epoch radial velocities for 28 stars observed with the Hobby-Eberly Telescope and its High Resolution Spectrograph between 2004 and 2013. Based on the observations gathered we present a low mass companion ($m_{p}\sin{i}$ = 10.6 $M_{J}$ in 1887.76 $\pm$ 0.01 d, 4.65 au orbit with $e$ = 0.59 $\pm$ 0.01) to a K giant BD+37 3172 ($M$=3.75$\pm$ 0.86 M$_{\odot}$), and a planetary mass companion (m$_{p}\sin{i}$=0.55 M$_{J}$ in 123.05$\pm$0.04 day, 0.55 au orbit with e=0.73$\pm$0.03) to a K giant BD+42 2315 ($M$=1.38$\pm$ 0.30 M$_{\odot}$). We also present two preliminary detections of new spectroscopic binaries: BD+56 2957 (K5) and HD 236555 (G5).

astro-ph.SR↗

arXiv2025

Low-mass companions to nine stars

We present an independent spectroscopic and radial velocity analysis for nine stars from the Pennsylvania-Toru\'n Planet Search. For BD+24 4697, we present an updated true companion's mass (0.16$\pm$0.02 \, M$_{\odot}$), as well as evidence of stellar activity. For BD+54 1640 and BD+65 1241 we present true masses of companions, $m = 0.15 \pm 0.04\,M_\odot$ and $m = 0.091 \pm 0.005\,M_\odot$, respectively. For BD+63 974 and BD+69 935 we find low mass companions with $m \sin i = 0.046 \pm 0.001\,M_\odot$ and $m \sin i = 0.090 \pm 0.005\,M_\odot$. For BD+52 1281, BD+54 1382, TYC 2704-2680-1, and TYC 3525-02043-1 we present evidence of low-mass companions with $m \sin i$ of 0.115 $\pm 0.006\,M_\odot$, 0.083 $\pm 0.007\,M_\odot$, 0.279 $\pm 0.009\,M_\odot$, and $0.064 \pm 0.006\,M_\odot$, respectively. Consequently, BD+54 1382, BD+63 974, BD+65 1241, BD+69 935 and TYC 3525-02043-1 appear to be Brown Dwarf host candidates.

astro-ph.SR↗

arXiv2025

The NGC3109 Satellite System: The First Systematic Resolved Search for Dwarf Galaxies Around a SMC-mass Host

We report the results of the deepest search to date for dwarf galaxies around NGC3109, a barred spiral galaxy with a mass similar to that of the Small Magellanic Cloud (SMC), using a semi-automated search method. Using the Dark Energy Camera (DECam), we survey a region covering a projected distance of $\sim$70 kpc of NGC 3109 ($D$ = 1.3 Mpc, $R_\mathrm{vir}\sim$ 90 kpc, $M\sim10^8M_\ast$) as part of the MADCASH and DELVE-DEEP programs. Through our resolved and newly designed semi-resolved searches, we successfully recover the known satellites Antlia and Antlia B. We identified a promising candidate, which was later confirmed to be a background dwarf through deep follow-up observations. Our detection limits are well defined, with the sample $\sim 80\%$ complete down to $M_V\sim-$8.0 , and includes detections of dwarf galaxies as faint as $M_V\sim-$6.0. This is the first comprehensive study of a satellite system through resolved star around an SMC mass host. Our results show that NGC 3109 has more bright ($M_V\sim-$9.0) satellites than the mean predictions from cold dark matter (CDM) models, but well within the host-to-host scatter. A larger sample of LMC/SMC-mass hosts is needed to test whether or not the observations are consistent with current model expectations.

astro-ph.GA↗

arXiv2025

DELVE-DEEP Survey: The Faint Satellite System of NGC 55

We report the first comprehensive census of the satellite dwarf galaxies around NGC 55 ($2.1$ Mpc) as a part of the DECam Local Volume Exploration DEEP (DELVE-DEEP) survey. NGC 55 is one of four isolated, Magellanic analogs in the Local Volume around which DELVE-DEEP aims to identify faint dwarfs and other substructures. We employ two complementary detection methods: one targets fully resolved dwarf galaxies by identifying them as stellar over-densities, while the other focuses on semi-resolved dwarf galaxies, detecting them through shredded unresolved light components. As shown through extensive tests with injected galaxies, our search is sensitive to candidates down to $M_V \lesssim -6.6$ and surface brightness $\mu \lesssim 28.5$ mag arcsec$^{-2}$, and $\sim 80\%$ complete down to $M_V \lesssim -7.8$. We do not report any new confirmed satellites beyond two previously known systems, ESO 294-010 and NGC 55-dw1. We construct the satellite luminosity function of NGC 55 and find it to be consistent with the predictions from cosmological simulations. As one of the first complete luminosity functions for a Magellanic analog, our results provide a glimpse of the constraints on low-mass-host satellite populations that will be further explored by upcoming surveys, such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time.

astro-ph.GA↗

arXiv2024

The DELVE Quadruple Quasar Search I. A Lensed Low Luminosity AGN

A quadruply lensed source, J125856.3-031944, has been discovered using the DELVE survey and WISE W1 - W2 colors. Followup direct imaging carried out with the Magellan Baade 6.5 m telescope is analyzed, as is spectroscopy from the 2.5 m Nordic Optical Telescope. The lensed image configuration is kite-like, with the major axis of the lensing galaxy along the symmetry axis of the kite, and with the faintest image at its tail. Redward of 6000 AA the tail image is strongly blended with the lensing galaxy. The Sloan g direct imaging carried out with Magellan permits deblending. As the lensed image configuration is nearly circular, simple models give high predicted magnifications for all four images. The source's narrow emission lines at redshift z=2.225 and low intrinsic luminosity qualify it as a Type 2 AGN. The Magellan image shows a substantial residual that suggests a second lensing galaxy.

astro-ph.CO↗

arXiv2021

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N VII. Elder suns with low-mass companions

We present the current status of and new results from our search for exoplanets in a sample of solar-mass, evolved stars observed with the HARPS-N and the 3.6-m Telescopio Nazionale Galileo (TNG), and the High Resolution Spectrograph (HRS) and the 9.2-m Hobby Eberly Telescope (HET). The aim of this project is to detect and characterise planetary-mass companions to solar-mass stars in a sample of 122 targets at various stages of evolution from the main sequence (MS) to the red giant branch (RGB), mostly sub-gaints and giants, selected from the Pennsylvania-Toruń Planet Search (PTPS) sample, and use this sample to study relations between stellar properties, such as metallicity, luminosity, and the planet occurrence rate. This work is based on precise radial velocity (RV) measurements. We have observed the program stars for up to 11 years with the HET/HRS and the TNG/HARPS-N. We present the analysis of RV measurements with the HET/HRS and the TNG/HARPS-N of four solar-mass stars, HD 4760, HD 96992 , BD+02 3313, and TYC 0434-04538-1. We found that: HD 4760 hosts a companion with a minimum mass of 13.9 MJ (a=1.14 au, e=0.23); HD 96992 is a host to a msin i=1.14 MJ companion on a a=1.24 au and e=0.41 orbit, and TYC 0434-04538-1 hosts an msin i=6.1MJ companion on a a=0.66 au and e=0.08$ orbit. In the case of BD+02 3313 we found a correlation between the measured RVs and one of the stellar activity indicators, suggesting that the observed RV variations may originate in either stellar activity or be caused by the presence of an unresolved companion. We also discuss the current status of the project and a statistical analysis of the RV variations in our sample of target stars.

astro-ph.EP↗

arXiv2009

Is there a metallicity enhancement in planet hosting red giants?

The Penn State/Toruń Centre for Astronomy Search for Planets Around Evolved Stars is a high-precision radial velocity (RV) survey aiming at planets detection around giant stars. It is based on observations obtained with the 9.2 m Hobby-Eberly Telescope. As proper interpretation of high precision RV data for red giants requires complete spectral analysis of targets we perform spectral modeling of all stars included in the survey. Typically, rotation velocities and metallicities are determined in addition to stellar luminosities and temperatures what allows us to estimate stellar ages and masses. Here we present preliminary results of metallicity studies in our sample. We search a metallicity dependence similar to that for dwarfs by comparing our results for a sample of 22 giants earlier than K5 showing significant RV variations with a control sample of 58 relatively RV-stable stars.

astro-ph.SR↗

arXiv2009

A Search for Planets with SALT

As the SALT High Resolution Spectrograph completion is nearing we plan to extend the Pennsylvania-Torun Planets Search (PTPS) with HET to the southern hemisphere. Due to overlap of the skies available for both HET and SALT in the declination range (+10, -10) deg some cooperation and immediate follow up is possible. Here we present, as an example, a $\sim$ 1000 star sample of evolved stars for the future SALT Planet Search.

astro-ph.EP↗