Hidden Depths in the Local Universe: the Stellar Stream Legacy Survey

Martínez–Delgado, David; Cooper, Andrew P.; Román, Javier San; Pillepich, Annalisa; Erkal, Denis; Pearson, Sarah; Moustakas, John; Laporte, Chervin F. P.; Laine, Seppo; Akhlaghi, Mohammad; Lang, Dustin; Макаров, Д. И.; Borlaff, Alejandro S.; Donatiello, Giuseppe; Pearson, William; Miro-Carretero, Juan; Cuillandre, J. C.; Domínguez, Helena; Roca-Fàbrega, S.; Frenk, Carlos S.; Schmidt, J.; Gómez-Flechoso, M. Á.; Guzmán, R.; Libeskind, Noam I.; Dey, Arjun; Weaver, B. A.; Schlegel, David J.; Myers, Adam D.; Valdés, F.

doi:10.48550/arxiv.2104.06071

Cited by 27 publications

(32 citation statements)

References 109 publications

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“…As pollutants are more visible in the r-band than in the g-band, they will tend to redden all measures. Nevertheless, our measure of the color of streams surrounding ETGs, with a median g − r value of 0.64 mag, is in agreement with Martinez-Delgado et al (2021) who determined a g − r value between 0.5 and 0.8 mag for 24 streams around local galaxies.…”

Section: Colorsupporting

confidence: 92%

“…One should note that most of the techniques mentioned above, whether applied to observational images or simulated ones, focus on qualitative aspects such as the probability of presence of one or several tidal features. Quantitative morphological and photometric measurements of tidal debris have so far been made for very limited numbers of galaxies (e.g., Martinez-Delgado et al 2021), or restricted to ongoing tidally interacting systems. Systematic measurements for larger samples are needed to fully characterize the various types of LSB structures in order to make quantitative comparisons with numerical simulation-based models of galaxy evolution.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of low surface brightness structures in annotated deep images

Sola

Duc

Richards

et al. 2022

A&A

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Context. The identification and characterization of low surface brightness (LSB) stellar structures around galaxies such as tidal debris of ongoing or past collisions is essential to constrain models of galactic evolution. So far most efforts have focused on the numerical census of samples of varying sizes, either through visual inspection or more recently with deep learning. Detailed analyses including photometry have been carried out for a small number of objects, essentially because of the lack of convenient tools able to precisely characterize tidal structures around large samples of galaxies. Aims. Our goal is to characterize in detail, and in particular obtain quantitative measurements, of LSB structures identified in deep images of samples consisting of hundreds of galaxies. Methods. We developed an online annotation tool that enables contributors to delineate the shapes of diffuse extended stellar structures with precision, as well as artifacts or foreground structures. All parameters are automatically stored in a database which may be queried to retrieve quantitative measurements. We annotated LSB structures around 352 nearby massive galaxies with deep images obtained with the Canada-France-Hawaii Telescope as part of two large programs: Mass Assembly of early-Type GaLAxies with their fine Structures (MATLAS) and Ultraviolet Near Infrared Optical Northern Survey (UNIONS)/Canada-France Imaging Survey (CFIS). Each LSB structure was delineated and labeled according to its likely nature: stellar shells, streams associated with a disrupted satellite, tails that formed in major mergers, ghost reflections, or cirrus. Results. From our database containing 8441 annotations, the area, size, median surface brightness, and distance to the host of 228 structures were computed. The results confirm the fact that tidal structures defined as streams are thinner than tails, as expected by numerical simulations. In addition, tidal tails appear to exhibit a higher surface brightness than streams (by about 1 mag), which may be related to different survival times for the two types of collisional debris. We did not detect any tidal feature fainter than 27.5 mag arcsec −2 , while the nominal surface brightness limits of our surveys range between 28.3 and 29 mag arcsec −2 , a difference that needs to be taken into account when estimating the sensitivity of future surveys to identify LSB structures. Conclusions. We compiled an annotation database of observed LSB structures around nearby massive galaxies including tidal features that may be used for quantitative analysis and as a training set for machine learning algorithms.

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Section: Colorsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Characterization of low surface brightness structures in annotated deep images

Sola

Duc

Richards

et al. 2022

A&A

Self Cite

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“…These data were reprocessed using the legacypipe software of the DESI Legacy imaging surveys (see, for example, Fig. 2 in Martinez-Delgado et al 2021a). In short, each image is astrometrically calibrated to Gaia-DR2 and photometrically calibrated to the Pan-STARRS PS1 survey, and then resampled to a common pixel grid and summed with inverse-variance weighting.…”

Section: Image Cutout Datamentioning

confidence: 99%

Tracing satellite planes in the Sculptor group: I. Discovery of three faint dwarf galaxies around NGC 253

Martinez-Delgado,

Makarov,

Javanmardi

et al. 2021

Preprint

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Context. In the last years, a new generation of large-scale imaging surveys have probed for the first time wide field regions around some nearby galaxies at unprecedented low surface brightness regime (∼ 28.0-29.0 mag arcsec −2 ). This offers a chance of discovering very faint dwarf satellites by means of systematic visual inspection of these public deep images. Aims. In this paper we report the first results of a systematic survey of faint dwarf spheroidal galaxies in the vicinity of the bright late-type spiral NGC 253 galaxy by means of a visual inspection of the images taken by the Dark Energy Survey. Methods. We performed a new NGC 253 satellite search using coadded image cutouts reprocessed in the DESI Legacy imagen surveys. We used galfit software for the photometric and structural properties of three dwarf galaxies. Results. Three new dwarf galaxies have been discovered in the vicinity of the brightest member of the Sculptor filament, the late-type spiral NGC 253, located at a distance of 3.7 Mpc towards Anti-Virgo. We named them Do II, Do III and Do IV. Assuming they are companions of NGC 253, their total absolute V-magnitudes fall in the −7 to −9 mag range, which is typical for dwarf satellites in the local Universe.The central surface brightness tend to be extremely low for all the discovered dwarfs and fall roughly in the range of 25-26 mag arcsec −2 in g-band. Using known data on distances and velocities of galaxies, we estimate the total virial mass of the NGC 253 group to be 8 × 10 11 M , which gives the virial radius R 200 = 186 kpc and the turn-around radius of 706 kpc. We also discuss the possible existence of a spatially flattened and velocity-correlated satellite system around NGC 253. This large-scale structure is orientated almost edge-on to line of sight. The possible plane of satellites is only 31 kpc thick with the minor-to-major axis ratio of 0.14. Four out of five galaxies with measured velocities follow a common velocity trend similar to those observed in the planes of satellites around the Andromeda and Centaurus A galaxies. However, the small number of galaxies with known velocities prevents to reach a definitive conclusion about the formation scenario of the structure and its possible relation to the surrounding cosmic web.

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“…Fig. 2 in Martinez-Delgado et al 2021). In short, each image including our target galaxy is astrometrically calibrated to Gaia-DR2 and photometrically calibrated to the Pan-STARRS PS1 survey, and subsequently resampled to a common pixel grid and summed with inverse-variance weighting.…”

Section: Desi Imaging Legacy Surveys and Galex Archival Datamentioning

confidence: 99%

Once in a blue stream: Detection of recent star formation in the NGC 7241 stellar stream with MEGARA

Martínez–Delgado¹,

Roca-Fàbrega²,

Paz³

et al. 2021

Preprint

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The census of stellar tidal streams around nearby massive galaxies has significantly grown from recent deep imaging of the low-surface brightness sky. In this work we study the striking case of a blue narrow stream with a possible globular clusterlike progenitor around the Milky Way-size galaxy NGC 7241 and its foreground dwarf companion. We present a follow-up spectroscopic study of this stream based on data taken with the MEGARA instrument at the 10.4-m Gran Telescopio Canarias using the integral field spectroscopy mode. Although our data suggest that this compact object in the stream is actually a foreground Milky Way halo star, we detect emission lines overlapping a less compact, bluer and fainter blob of the stream that is clearly visible in both ultra-violet and optical deep images. From its heliocentric systemic radial velocity derived from the [O ]𝜆5007Å lines (𝑉 syst = 1548.58±1.80 km s −1 ) and new UV and optical broad-band photometry, we conclude that this over-density could be the actual core of the stream, with an absolute magnitude of M𝑔 ∼ -10 and a 𝑔 − 𝑟 = 0.08 ± 0.11, consistent with a remnant of a low-mass dwarf satellite undergoing a current episode of star formation. From the width of the stream and assuming a circular orbit, we calculate that the progenitor mass is between 6.4 × 10 6 M − 2.7 × 10 7 M , which is typical of a dwarf galaxy, but its mass could be substantially lower if the stream is on a very radial orbit. These estimates also suggest that this is one of the lowest mass streams detected so far beyond the Local Group. We find that blue stellar streams containing star formation regions are commonly predicted by high-resolution cosmological simulations of galaxies lighter than the Milky Way. This scenario is consistent with the processes explaining the bursty star formation history of some dwarf satellites, which are followed by a gas depletion and a fast quenching once they enter within the virial radius of their host galaxies for the first time. Thus, it is likely that the stream's progenitor is suffering a star-formation burst comparable to those that have shaped the star-formation history of several Local Group dwarfs in the last few Gigayears.

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Hidden Depths in the Local Universe: the Stellar Stream Legacy Survey

Cited by 27 publications

References 109 publications

Characterization of low surface brightness structures in annotated deep images

Characterization of low surface brightness structures in annotated deep images

Tracing satellite planes in the Sculptor group: I. Discovery of three faint dwarf galaxies around NGC 253

Once in a blue stream: Detection of recent star formation in the NGC 7241 stellar stream with MEGARA

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