adsabs/AstroCLIMB huggingface dataset:
Paper: Two Novel Hot Jupiter Formation Pathways: How White Dwarf Kicks Shape the Hot Jupiter Population
Authors: Alexander P. Stephan, David V. Martin, Smadar Naoz, Nathan R. Hughes, Cheyanne Shariat
Figure caption: Evolution of a binary star System with a WD formation kick after HJ formation. Shown is the evolution of a Jupiter-like planet orbiting in a binary star system and the outcomes of the WD formation kick. The upper row of panels shows the mutual inclination between the planetary and stellar binary orbits. In the middle row of panels, the red and blue lines show the planet’s SMA and periapsis distance, respectively; the cyan line shows the planet’s Roche limit and the green and yellow lines show the stellar companion’s SMA and periapsis distance, respectively. Note that the planet undergoes eccentricity oscillations due to the EKL mechanism, leading to tidal migration and circularization as an HJ at around 0.77 Gyr into the system’s evolution. We determine that tidal decay after circularization is minimal for the planet, such that it will approximately remain in its orbit from that point onwards. At around 3.2 Gyr, the more massive stellar companion evolves off the MS, becoming first a red giant and finally a WD. The mass loss during that process results in an expansion of the companion’s SMA and periapsis distance. Finally, we include the effects of the WD formation kick following K. El-Badry & H.-W. Rix (2018), which results in a new mutual orbital inclination and new companion SMA and periapsis in ∼40% of cases, which, for this particular system, follow the blue, green, and yellow distributions in the three plots on the bottom of the figure, respectively. The stellar binary is separated in ∼60% of cases for this system. The right column of panels shows one random example of surviving system parameters. The planet host star has an initial mass of m1 = 0.516 M⊙; the planet has the mass and radius of Jupiter and an initial orbit SMA of a1 = 4.935 au and eccentricity of e1 = 0.01; and the stellar companion has an initial mass of m3 = 1.486 M⊙, initial orbit SMA of a2 = 1072﹩\mathop{.}\limits^{\circ }﹩766 au, and eccentricity of e2 = 0.913. The planetary and stellar orbits have an initial mutual inclination of inc =107﹩\mathop{.}\limits^{\circ }﹩091 and arguments of periapsis of ω1 = 111﹩\mathop{.}\limits^{\circ }﹩704 and ω2 = 252﹩\mathop{.}\limits^{\circ }﹩729, respectively. The stellar radii and mass loss are calculated by SSE throughout the evolution.
Paper: Two Novel Hot Jupiter Formation Pathways: How White Dwarf Kicks Shape the Hot Jupiter Population
Authors: Alexander P. Stephan, David V. Martin, Smadar Naoz, Nathan R. Hughes, Cheyanne Shariat
Figure caption: Evolution of a binary star system that forms an HJ due to a WD formation kick. The line colors used in this plot correspond to the same parameters as shown in Figure 2. Unlike the system shown in Figure 2, the system shown here does not undergo EKL oscillations at the beginning (left column of panels) as the mutual inclination of the planetary and stellar binary orbits is too small. However, the WD formation kick (middle column of panels) is able to alter the companion inclination, SMA, and eccentricity sufficiently to trigger EKL evolution, which eventually leads to HJ formation (right column of panels). The planet host star has an initial mass of m1 = 0.930 M⊙; the planet has the mass and radius of Jupiter and an initial orbit SMA of a1 = 7.583 au and eccentricity of e1 = 0.01; and the stellar companion has an initial mass of m3 = 1.683 M⊙, initial orbit SMA of a2 = 791.617 au and eccentricity of e2 = 0.784. The planetary and stellar orbits have an initial mutual inclination of inc =38﹩\mathop{.}\limits^{\circ }﹩523 and arguments of periapsis of ω1 = 64﹩\mathop{.}\limits^{\circ }﹩291 and ω2 = 90﹩\mathop{.}\limits^{\circ }﹩128, respectively.
Paper: Two Novel Hot Jupiter Formation Pathways: How White Dwarf Kicks Shape the Hot Jupiter Population
Authors: Alexander P. Stephan, David V. Martin, Smadar Naoz, Nathan R. Hughes, Cheyanne Shariat
Figure caption: Cartoon diagrams of our two proposed novel formation pathways for HJs. Pathway 1 (top): a cold Jupiter is turned into an HJ through EKL oscillations under the influence of a misaligned and more massive outer stellar companion. The more massive star evolves into a WD and receives a large velocity kick due to asymmetric mass loss. This kick ionizes the binary, leaving behind an HJ orbiting a single star. Pathway 2 (bottom): a cold Jupiter is in a stellar binary where no EKL oscillations occur because the binary is not sufficiently misaligned with respect to the planet. The outer star, which is more massive, evolves into a WD. It receives a moderate velocity kick that misaligns the binary but does not ionize it, which in turn allows EKL oscillations to commence and leads to HJ formation.
Paper: Tracing Back a Second-generation Star Stripped from Terzan 5 by the Galactic Bar
Authors: Stefano O. Souza, Marica Valentini, Cristina Chiappini, Angeles Pérez-Villegas, Josefina Montalbán, Diego Bossini, Beatriz Barbuy, Yvonne Elsworth, Rafael A. Garcia
Figure caption: Chronochemical comparison between SOS1 and Terzan 5. The abundances of α elements, C, and Al vs. the iron content [Fe/H] for Terzan 5 (L. Origlia et al. 2011, 2013; blue) and SOS1 (yellow). The arrow in each panel shows the average maximum difference (A. P. Milone et al. 2018) between 1G (dotted line) and 2G for a metallicity around [Fe/H] = −1.0, the Terzan 5's popC (the arrows are shifted in the x-axis to make the plot clearer). The rightmost panel shows the age distribution for Terzan 5 (black histogram) compared to different age determinations for SOS1 (colored lines).
Paper: Tracing Back a Second-generation Star Stripped from Terzan 5 by the Galactic Bar
Authors: Stefano O. Souza, Marica Valentini, Cristina Chiappini, Angeles Pérez-Villegas, Josefina Montalbán, Diego Bossini, Beatriz Barbuy, Yvonne Elsworth, Rafael A. Garcia
Figure caption: Verification of APOGEE-ASPCAP abundances. Upper panels: spectrum synthesis of Al. The colored lines represent synthetic spectra with no Al abundance (blue), solar Al abundance (orange), and [Al/Fe] = 1.17 (green—the value provided by APOGEE). Bottom panels: spectrum synthesis of C, N, and O. The blue line is the normal CNO abundance set [C, N, O/Fe] = (0.0, 0.0, +0.40) and the orange line [C, N, O/Fe] = (–0.15, +0.60, +0.06) and green line [C, N, O/Fe] = (–0.31, +1.15, +0.13) the set provided by APOGEE.
Paper: Tracing Back a Second-generation Star Stripped from Terzan 5 by the Galactic Bar
Authors: Stefano O. Souza, Marica Valentini, Cristina Chiappini, Angeles Pérez-Villegas, Josefina Montalbán, Diego Bossini, Beatriz Barbuy, Yvonne Elsworth, Rafael A. Garcia
Figure caption: Verification of the APOGEE-ASPCAP abundances of Al (upper panels) and N (bottom panels): comparison of spectra of the sample star SOS1 (red line) with a reference star (STARB) with similar stellar parameters and solar abundances (blue line).
Paper: Tracing Back a Second-generation Star Stripped from Terzan 5 by the Galactic Bar
Authors: Stefano O. Souza, Marica Valentini, Cristina Chiappini, Angeles Pérez-Villegas, Josefina Montalbán, Diego Bossini, Beatriz Barbuy, Yvonne Elsworth, Rafael A. Garcia
Figure caption: Derivation of the abundance contribution for the elements O, Mg, Si, C, Al, and N due to the MPs.
Paper: ALMA Detection of [O III] 88 μm at z = 12.33: Exploring the Nature and Evolution of GHZ2 as a Massive Compact Stellar System
Authors: Jorge A. Zavala, Tom Bakx, Ikki Mitsuhashi, Marco Castellano, Antonello Calabro, Hollis Akins, Veronique Buat, Caitlin M. Casey, David Fernandez-Arenas, Maximilien Franco, Adriano Fontana, Bunyo Hatsukade, Luis C. Ho, Ryota Ikeda, Jeyhan Kartaltepe, Anton M. Koekemoer, Jed McKinney, Lorenzo Napolitano, Pablo G. Pérez-González, Paola Santini, Stephen Serjeant, Elena Terlevich, Roberto Terlevich, L. Y. Aaron Yung
Figure caption:  The Hβ line luminosity–velocity dispersion relationship. The position of GHZ2 in the L–σ relationship for Giant H II regions and H II-galaxies is represented by the yellow star (adopting the lensing-corrected L Hβ  reported in J. A. Zavala et al. 2024 and the line width from the ALMA [O III] 88 μm detection reported in this work). As can be seen, the z = 12 galaxy follows the relation found for H II-galaxies (as reported by J. Melnick et al. 2017; solid purple line and shaded region), suggesting a similar nature for both objects: young burst of star formation. The three orange solid triangles show z ≈ 6–7 H II-galaxies recently identified (R. Chávez et al. 2024), while the open orange triangle represents MACS0647-JD at z = 10.2 (T. Y.-Y. Hsiao et al. 2024b). Finally, we plot the high-redshift AGN sample from A. J. Taylor et al. (2024) and R. Maiolino et al. (2024b) as solid and open squares, respectively, and indicate the position of more massive AGN at z ∼ 2 (D. Kakkad et al. 2020) with green arrorows. The AGN deviate from the relationship for H II-dominated systems.
Paper: ALMA Detection of [O III] 88 μm at z = 12.33: Exploring the Nature and Evolution of GHZ2 as a Massive Compact Stellar System
Authors: Jorge A. Zavala, Tom Bakx, Ikki Mitsuhashi, Marco Castellano, Antonello Calabro, Hollis Akins, Veronique Buat, Caitlin M. Casey, David Fernandez-Arenas, Maximilien Franco, Adriano Fontana, Bunyo Hatsukade, Luis C. Ho, Ryota Ikeda, Jeyhan Kartaltepe, Anton M. Koekemoer, Jed McKinney, Lorenzo Napolitano, Pablo G. Pérez-González, Paola Santini, Stephen Serjeant, Elena Terlevich, Roberto Terlevich, L. Y. Aaron Yung
Figure caption:  The SFR–[O III] line luminosity relationship. The open symbols represent the sample of low-redshift (z ≲ 0.3) galaxies presented in I. De Looze et al. (2014), with purple circles representing metal-poor “dwarf” galaxies, green open circles for more massive star-forming galaxies, green open squares for composite/AGN, and green open triangles for ultraluminous infrared galaxies. The relationships derived by I. De Looze et al. (2014) are also plotted as solid, dashed, and dotted lines for the population of metal-poor “dwarf” galaxies, star-forming galaxies, and composite/AGN, respectively. Solid symbols represent high-redshift galaxies (z ≈ 5–9; as compiled in H. S. B. Algera et al. 2024 and T. J. L. C. Bakx et al. 2024), with purple circles for LBGs/LAEs, green circles for submillimeter galaxies, and green squares for QSOs. Our target, GHZ2, is represented by the yellow star (adopting the range of SFRs from J. A. Zavala et al. 2024 and correcting from magnification), and along with other high-z LBGs, it nicely follows the local relationship for metal-poor “dwarf” galaxies. Note that the metallicity of GHZ2 is constrained to be Z ≈ 0.05−0.1 Z ⊙ (A. Calabro et al. 2024; M. Castellano et al. 2024; J. A. Zavala et al. 2024).
Paper: ALMA Detection of [O III] 88 μm at z = 12.33: Exploring the Nature and Evolution of GHZ2 as a Massive Compact Stellar System
Authors: Jorge A. Zavala, Tom Bakx, Ikki Mitsuhashi, Marco Castellano, Antonello Calabro, Hollis Akins, Veronique Buat, Caitlin M. Casey, David Fernandez-Arenas, Maximilien Franco, Adriano Fontana, Bunyo Hatsukade, Luis C. Ho, Ryota Ikeda, Jeyhan Kartaltepe, Anton M. Koekemoer, Jed McKinney, Lorenzo Napolitano, Pablo G. Pérez-González, Paola Santini, Stephen Serjeant, Elena Terlevich, Roberto Terlevich, L. Y. Aaron Yung
Figure caption:  Constraints on the oxygen electron density. Predicted 52–88 μm luminosity ratio as a function of electron density generated using PYNEB (V. Luridiana et al. 2015). This ratio is nearly independent to gas temperature, ionization parameter, and metallicity. The 3σ upper limit from our observations (orange star) rules out high-density environments, such as those found in GNz-11 (>109 cm−3). The comparison data come from the PACS and SPIRE spectrometry of nearby star-forming galaxies (J. A. Fernández-Ontiveros et al. 2016). The solid green symbols indicate the oxygen-derived electron densities, which accurately follow the theoretical predictions, while the semitransparent symbols indicate complementary probes of the electron densities (using [N II] 205/122, [S III] 33/18, and [Ne V] 24/14 ratios). As can be seen, star-forming galaxies show moderate electron densities, consistent with the inferred limit for GHZ2.
Paper: ALMA Detection of [O III] 88 μm at z = 12.33: Exploring the Nature and Evolution of GHZ2 as a Massive Compact Stellar System
Authors: Jorge A. Zavala, Tom Bakx, Ikki Mitsuhashi, Marco Castellano, Antonello Calabro, Hollis Akins, Veronique Buat, Caitlin M. Casey, David Fernandez-Arenas, Maximilien Franco, Adriano Fontana, Bunyo Hatsukade, Luis C. Ho, Ryota Ikeda, Jeyhan Kartaltepe, Anton M. Koekemoer, Jed McKinney, Lorenzo Napolitano, Pablo G. Pérez-González, Paola Santini, Stephen Serjeant, Elena Terlevich, Roberto Terlevich, L. Y. Aaron Yung
Figure caption:  Detection of the [OIII] 88 μm transition at z = 12.3. The left panel shows the 3.″5 × 3.″5 moment-0 map of the line, along with the ALMA beam size (black ellipse) and the JWST NIRCam position of GHZ2 (black cross). Contours show SNR in steps of ±1σ (with dashed lines for negative values). The ∼5σ detection from ALMA is in very good agreement with the JWST position. The extracted spectrum from the peak pixel is shown on the right panel along with the best-fit Gaussian function (red solid line) and associated uncertainty (gray lines; see the main text for details), implying a spectroscopic redshift of z = 12.3327 ± 0.0035. On the top, we show the associated redshifts inferred from the different instruments, including NIRSpec, MIRI, and ALMA. Thanks to the higher spectral resolution of the ALMA observations, the redshift precision is increased by ∼5×.
Paper: Protosolar D-to-H Abundance and One Part per Billion PH3 in the Coldest Brown Dwarf
Authors: Melanie J. Rowland, Caroline V. Morley, Brittany E. Miles, Genaro Suarez, Jacqueline K. Faherty, Andrew J. Skemer, Samuel A. Beiler, Michael R. Line, Gordon L. Bjoraker, Jonathan J. Fortney, Johanna M. Vos, Sherelyn Alejandro Merchan, Mark Marley, Ben Burningham, Richard Freedman, Ehsan Gharib-Nezhad, Natasha Batalha, Roxana Lupu, Channon Visscher, Adam C. Schneider, T. R. Geballe, Aarynn Carter, Katelyn Allers, James Mang, Dániel Apai, Mary Anne Limbach, Mikayla J. Wilson
Figure caption: The JWST/NIRSpec G395M spectrum with error bars of WISE 0855 for GTO program 1230 (PI: Alves de Oliveira; top) and GO program 2327 (PI: Skemer; bottom); the 1σ retrieved spectrum and the residuals from the median retrieved spectrum are shown in black, blue, and gray. The differences between the best-fit spectrum and the best-fit spectrum with PH3 or CH3D opacity removed are plotted in shaded green and orange, respectively. The regions where each opacity has the largest effect on the spectrum (≈10%) are highlighted in subpanels, showing that both PH3 or CH3D are detected in both data sets. The GTO data set has a mean S/N of 107, and the GO data set has a mean S/N of 759.
Paper: 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, Sébastien Lambert
Figure caption: VLBI-measured position offsets of the ICRF3 source IERS B1334−127 with respect to its maximum-likelihood mean position. Left: offsets in tangential sky coordinates x (R.A.) and y (decl.) in milliarcseconds. Right: standardized offsets {ux, uy} (Equation (1)) relative to the same mean position.
Paper: 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, Sébastien Lambert
Figure caption: A 15 GHz MOJAVE image of 0607−157 (M. L. Lister et al. 2018), clearly showing emission in multiple extended regions. The scatter points are the astrometric time series, colored by time, and are smoothed over a rolling 4 month time window as described in P. Cigan et al. (2024). The red arrows correspond to the jet angles and median distances determined by A. V. Plavin et al. (2022) at various frequencies, and the blue arrow corresponds to the same at 8 GHz. The yellow arrow denotes the angle of preferred astrometric excursion ϑast.
Paper: 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, Sébastien Lambert
Figure caption: X-band image of B1038+52A from USNO’s FRIDA database (https://crf.usno.navy.mil/FRIDA), observed on 2008 January 23. The hatched ellipse denotes the beam FWHM. The astrometric measurements, smoothed over a rolling 4 month time window as described in P. Cigan et al. (2024) to enhance the visibility of coherent trends, are overlaid as scatter points colored by time.
Paper: 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, Sébastien Lambert
Figure caption: Histogram of differences between the position angles of preferred astrometric excursions determined in this Letter (ϑast) and the position angles of radio jets (ϑjet) from A. V. Plavin et al. (2022), modulo π.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: Spectroscopic (top panel) and photometric (middle and bottom panels) measurements of the Bernhard-2 system. The solid line in each panel represents the best-fit model. The gray shaded region in the top panel is the 1σ uncertainty of the RV model. In the top panel, the blue, orange, and green points are the RV measurements from GTC, KPF, and FIRE, respectively. Note that we assume the FIRE data point has the same RV offset with KPF. GTC and FIRE measurements that are not used in the RV modeling are indicated by crosses. The new photometric measurements are taken in r (middle panel) and i (bottom panel) bands. The new light curves do not agree with the best-fit model of W. Zhu et al. (2022), which may suggest some substantial precession of the circumbinary disk.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: The phase-folded RV fitting result (upper panel) and the corresponding GTC Hα profiles (lower panel). The description of data points and model in the upper panel is the same as Figure 1 except for the number above each GTC data point, which labels the observations in ascending phase order. Note that the bold numbers with asterisk are the observations with inverse P-Cygni Hα profile. The pericenter passage time is shown with the purple solid line, respectively. The purple shaded region indicates the fitting error of TP. In the lower panels, we show the observed spectra as well as the single-star template near the Hα region with blue and black solid lines, respectively. The number on the upper left of each panel is the observation label in the upper panel, while the number on the upper right indicates the corresponding phase. For a detailed discussion of the Hα profile, please refer to Section 4.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: The sky-projected view of the binary orbital dynamics and the boundary of the occulting disk in the Bernhard-2 system. In order to illustrate the orbital characteristics and the change in the disk edge position, we only show the model with the best-fitting parameters. The hatched area shows the updated position of the disk edge from our new photometric observations (detailed in Section 2.3), whereas the dashed line indicates the edge position reported in W. Zhu et al. (2022), which utilized ZTF data collected over the period from 2018 to 2021. The black and gray ellipses represent the primary and secondary orbits, respectively, which are constructed using the best-fitting RV and stellar parameters, assuming an arbitrary longitude of the ascending node. The blue, orange, and green circles denote the positions of the primary star when the observations were conducted with GTC OSIRIS, KPF, and Magellan FIRE, respectively. Similar to Figure 2, the GTC observations are indexed according to the orbital phases.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: SEDs at different phases and the best-fit binary model. Observations from Pan-STARRS, 2MASS, and WISE are shown in red, purple, and pink, respectively. The extent of each point along the wavelength direction indicates the corresponding bandwidth. The data obtained outside the occultation phase are shown in circles, while the data obtained inside the occultation phase are shown in squares. Note that points with an additional cross are not used in the fitting process. The orange dotted and blue dashed lines show the best-fit stellar SED model for the primary and secondary, respectively. The outside-occultation data are fitted by the summation of the two components, which is shown in the green solid line.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: The combined GTC spectrum and a few synthetic spectra around the 6708 Å Li I line. The black solid line represents the combined data, with the gray region indicating the 1σ uncertainty. The black dashed line shows the spectrum with no lithium. The spectra in orange, green, and red have lithium abundances A(Li) = 3.0, 3.68 (the best-fit value), and 4.0, respectively. The horizontal dashed line indicates the continuum level, while the vertical dashed line marks the center of the 6708 Å Li I line.
Paper: An Eccentric Binary with a Misaligned Circumbinary Disk
Authors: Zhecheng Hu, 哲程 胡, Wei Zhu, 伟 祝, Fei Dai, 飞 戴, Ping Chen, 平 陈, Yang Huang, 样 黄, Min Fang, 敏 房, Richard S. Post
Figure caption: The change of the fraction that the primary is not occulted, i.e., η, as a function of time. The gray dashed lines indicate the start and end of the ingress and egress, respectively.
Paper: ALMA Detection of [O III] 88 μm at z = 12.33: Exploring the Nature and Evolution of GHZ2 as a Massive Compact Stellar System
Authors: Jorge A. Zavala, Tom Bakx, Ikki Mitsuhashi, Marco Castellano, Antonello Calabro, Hollis Akins, Veronique Buat, Caitlin M. Casey, David Fernandez-Arenas, Maximilien Franco, Adriano Fontana, Bunyo Hatsukade, Luis C. Ho, Ryota Ikeda, Jeyhan Kartaltepe, Anton M. Koekemoer, Jed McKinney, Lorenzo Napolitano, Pablo G. Pérez-González, Paola Santini, Stephen Serjeant, Elena Terlevich, Roberto Terlevich, L. Y. Aaron Yung
Figure caption:  The stellar mass–velocity dispersion relationship. The velocity dispersion as a function of stellar mass (left) and stellar mass surface density (right) for different populations of pressure-supported systems (taken from M. A. Norris et al. 2014), including globular clusters (light-purple circles), UCDs (solid purple circles), dwarf ellipticals (down-pointing triangles), compact ellipticals (blue solid circles), and elliptical and S0 galaxies (green squares). Our target, GHZ2, represented by the yellow star, shows a similar stellar mass surface density as globular clusters but with a higher total stellar mass that is in better agreement with those of UCDs and compact ellipticals. Indeed, it occupies a similar locus as M32, the prototypical compact elliptical galaxy (represented by the up-pointing blue triangle). Note, however, that significant mass losses are expected due to stellar and dynamical evolution that would eventually affect the position of GHZ2 on this parameter space.